All Tools
124 tools available
Construction
Gravel Calculator
Calculate cubic yards and tons of gravel needed for driveways, paths, and landscaping.
Use ToolPaver, Base, and Bedding-Sand Estimator
Estimate pavers, base gravel volume, bedding sand volume, and edge restraint for a rectangular patio or walkway.
Use ToolSod Estimator
Calculate square feet, square yards, sod rolls, and pallet count for a rectangular lawn.
Use ToolAsphalt Driveway Estimator
Estimate tons of hot-mix asphalt and base gravel volume for a driveway or parking pad.
Use ToolMulch Refresh / Top-Up Estimator
Estimate how much mulch you need to top up an existing bed back to a target depth β uses the difference between current and target depth, not full-depth install.
Use ToolPaint Coverage Calculator
Estimate how many gallons of paint you need for a room based on wall dimensions, openings, and number of coats.
Use ToolDrywall Estimator
Estimate drywall sheets needed for a room using wall dimensions, optional ceiling coverage, openings area, waste, and common sheet sizes.
Use ToolTile & Flooring Estimator
Estimate total flooring area, waste-adjusted coverage, and number of boxes to buy for tile, vinyl plank, laminate, or engineered flooring.
Use ToolWallpaper Roll Calculator
Estimate wallpaper rolls from wall dimensions, openings, pattern repeat, and roll type.
Use ToolInsulation Coverage Estimator
Estimate fiberglass batts or blown cellulose / fiberglass quantities to insulate an area to a target R-value.
Use ToolCountertop Square Footage Estimator
Estimate countertop slab area including main runs, island, and backsplash, with configurable overage for fabrication waste.
Use ToolBaseboard Trim Estimator
Estimate linear feet of baseboard trim and stock sticks to buy for a room, deducting door openings and optional wall cutouts.
Use ToolCabinet Layout Estimator
Rough-count base, wall, corner, and tall cabinets for a straight, L, or U-shaped kitchen run. Planning-only β not a stock-cabinet specification.
Use ToolSheet Goods Cut Estimator
Estimate how many full sheets of plywood, drywall, MDF, OSB, or subfloor you need from total coverage area and sheet size.
Use ToolStair Carpet Estimator
Estimate carpet or runner material for a staircase using stair count, tread depth, riser height, stair width, and optional landing coverage.
Use ToolRoofing Material Estimator
Estimate roofing squares and shingle bundles from roof footprint area, pitch multiplier, waste, and bundle coverage.
Use ToolFence Material Estimator
Estimate panels, posts, gates, and concrete bags for a straight-run fence based on total length and post spacing.
Use ToolDeck Material Estimator
Estimate decking board count, joists, and fasteners for a rectangular deck based on deck dimensions, board width, and joist spacing.
Use ToolRetaining Wall Block Estimator
Estimate segmental retaining wall blocks, cap units, drainage gravel, and leveling pad for a straight-run retaining wall.
Use ToolBrick & Block Calculator
Estimate brick or concrete masonry unit (CMU) count and mortar bags from wall face area.
Use ToolRebar Grid Estimator
Estimate rebar linear feet, bar count, and overlap allowance for a rectangular slab grid.
Use ToolConcrete Block Fill Estimator
Estimate grout volume and 80-lb concrete bag count to fill CMU block cores β full fill, alternating cores, or bond-beam only.
Use ToolWater Pump Sizing Estimator
Suggest a target flow rate (GPM) and pressure band for a residential booster / well / transfer pump based on fixture count, vertical lift, and pipe run. Planning-only guidance β NOT an engineering specification.
Use ToolDrainage Slope Calculator
Convert between run length, fall (drop), percent slope, and inches-per-foot, with a verdict for hardscape drainage.
Use ToolFrench Drain Estimator
Estimate gravel volume, pipe length, and filter fabric for a perforated-pipe french drain trench.
Use ToolGravel Grid Driveway Estimator
Estimate plastic grid panels plus base and surface gravel for a permeable, grid-reinforced driveway.
Use ToolFinance
Auto Loan Calculator
Calculate your monthly car payment and total cost, including down payment, trade-in, and sales tax.
Use ToolCompound Interest Calculator
Project the future value of savings with compound interest and optional monthly contributions.
Use ToolMortgage Calculator
Calculate your monthly mortgage payment and total interest over the life of a loan.
Use ToolRetirement Projection
Project your retirement balance based on current savings, monthly contributions, and expected return. Shows both nominal and inflation-adjusted values.
Use ToolSavings Goal Calculator
Find out how long it will take to reach a savings goal with regular contributions.
Use ToolTip Calculator
Calculate the tip on a restaurant bill and split the total across multiple people.
Use ToolUS Federal Income Tax Estimator (2025)
Estimate your 2025 US federal income tax based on gross income, filing status, and deductions. Federal only β does not include state or payroll taxes.
Use ToolContingency Fee Split Calculator
Worksheet for plaintiff-side matters: estimate attorney fee, client recovery before liens, and client net after fees, costs, and liens.
Use ToolLaw Firm Retainer Burn Estimator
Estimate how fast a legal retainer will be consumed based on hourly rate, expected monthly hours, hard costs, and a replenishment threshold.
Use ToolBillable Hours Target Planner
Turn an annual billable-hours target into monthly, weekly, and daily targets, including required working hours per day at your utilization rate.
Use ToolMeeting Cost Calculator
Estimate what a meeting costs in salary dollars based on attendees, average salary, duration, and optional recurrence. Includes a fully-loaded cost option that adds benefits / overhead.
Use ToolFreelance Quote Builder
Build a freelance project quote from estimated hours, hourly rate, fixed costs, target margin, and optional rush fee. Shows labor, profit, and final quote.
Use ToolOvertime Cost Calculator
Calculate the total cost of overtime hours at 1.5Γ (time and a half), 2Γ (double time), or a custom multiplier. Shows the overtime premium separately from straight-time cost.
Use ToolEmergency Fund Target Planner
Compute how much emergency fund you need based on monthly expenses and a target-months cushion, and how long to build it at a given monthly save rate.
Use ToolSavings Goal Timeline
How long until you reach a savings goal, given a monthly contribution, a starting balance, and an annual interest rate.
Use ToolHome Maintenance Budget Estimator
Estimate how much to set aside for home maintenance annually, monthly, and weekly based on home value and an age-tier factor.
Use ToolCredit Card Fee / Interest Comparator
Compare two credit cards under a specific usage pattern: annual fee, APR on carried balance, and rewards rate on monthly spend.
Use ToolSubscription Cost Cutter
Total your recurring subscriptions and see monthly + annual savings from cutting the ones you flag as cancel.
Use ToolIrregular-Income Budget Planner
Derive a conservative safe monthly spending cap from your income history. Built for freelance / commission / variable-pay earners.
Use ToolTax Extension + Payment Planner
Recommended payment to submit with your extension to avoid underpayment interest. Uses IRS safe-harbor rules (100% or 110% of prior-year tax, or 90% of current-year estimate).
Use ToolHotel Value Comparator
Compare two hotel options by total cost (rate Γ nights + add-on fees + tax + expected cancellation risk) so the cheaper headline rate isn't the only factor.
Use ToolCarry-On vs. Checked Bag Optimizer
Compute whether checking a bag or flying carry-on is cheaper given your trips per year, typical fees, bag cost, and time value.
Use ToolSplit Rent by Income
Fair-share rent split for 2β4 housemates: proportional to income (each pays the same % of their pay) or equal (rent Γ· N). Side-by-side so you can pick what feels fair.
Use ToolHealth
BMI Calculator
Calculate your Body Mass Index (BMI) and see which WHO category it falls into.
Use ToolDaily Calorie Estimator
Estimate your daily calorie needs based on the Mifflin-St Jeor equation.
Use ToolDaily Hydration Calculator
Estimate how much water you should drink each day based on your weight and activity level.
Use ToolSleep Cycle Planner
Find the ideal bedtime to wake up feeling rested by timing sleep to complete full 90-minute cycles.
Use ToolBMI Healthy Weight Range
From your height, show the WHO/CDC BMI weight bands β underweight, healthy (18.5β24.9), overweight, and obesity thresholds β so you can see the full target range, not a single number.
Use ToolTravel
Packing List Generator
Generate a customized packing list based on your trip length, climate, and planned activities.
Use ToolTravel Entry Requirements (reference)
Get general entry-requirement guidance (passport validity, visa-waiver programs, common gotchas) for major destination regions.
Use ToolTrip Cost Estimator
Get a rough cost range for a trip based on destination region, duration, and travel style.
Use ToolTrip Cost Splitter
Split a shared trip cost evenly across people, netting out what each person has already paid so everyone sees who owes whom.
Use ToolWeekend Food Budget Estimator
Estimate food spend for a short trip by meal count and average per-meal cost.
Use ToolConverters
Percentage Calculator
Three-in-one: "What is X% of Y?", "X is what percent of Y?", and "What is the % change from X to Y?"
Use ToolUnit Price Comparer
Compare two package sizes to see which is cheaper per unit. Works for groceries, detergent, paint, bulk goods β anything sold at different sizes and prices.
Use ToolDecision Tools
Investment Style Guide
Get a suggested investment approach based on your risk tolerance and time horizon.
Use ToolBuy New vs Used β Decision Guide
A decision flow, not a calculator. Weighs budget, ownership horizon, reliability needs, warranty value, and depreciation sensitivity to recommend New / Certified Pre-Owned / Used. No fake TCO numbers β this is structured judgment.
Use ToolDecision Scorecard Builder
Score up to 4 options across up to 5 weighted criteria. Produces a ranked list with transparent weighted totals.
Use ToolCar Loan vs Lease β Decision Guide
Should you finance a car or lease one? Six structured questions about mileage, ownership horizon, cash priorities, and credit produce a recommendation: Lease / Buy New / Buy Used / Buy CPO. Honest planning aid β no fake monthly-payment numbers.
Use ToolGenerators
Content Outline Generator
Generate a structured content outline for articles, blog posts, and guides.
Use ToolEveryday
Date & Age Calculator
Calculate the days, weeks, months, and years between two dates. Works as an age calculator when the end date is today.
Use ToolFinal Exam Grade Needed
Figure out what score you need on your final exam to hit a target grade in the course.
Use ToolFuel Cost Calculator
Calculate the fuel cost of a trip based on distance, your vehicle's MPG, and gas price.
Use ToolGPA Calculator
Calculate your semester GPA on the standard 4.0 US scale. Enter each course's letter grade and credit hours.
Use ToolEV Charging Cost Estimator
Estimate the daily, monthly, and annual cost to charge an electric vehicle (Tesla, Rivian, Bolt, Ioniq, etc.) from miles driven, vehicle efficiency, electricity rate, and home-charger losses.
Use ToolDeadline Backwards Planner
Given a deadline and the total hours a project will take, figure out what date you should start and how many calendar days you'll need.
Use ToolGrocery Budget Planner
Estimate a weekly, monthly, and annual grocery budget from household size, USDA-style meal-plan tier, and eating-out frequency.
Use ToolMoving Box Estimator
Estimate the moving boxes, packing supplies, and dish packs you need based on your home's room count and packing density.
Use ToolStorage Unit Size Estimator
Recommend a storage unit size (5Γ5, 5Γ10, 10Γ10, 10Γ15, or 10Γ20) based on your belongings. Planning estimate β load patterns matter.
Use ToolTime Zone Overlap Finder
Find the overlapping work hours between two time zones so you can schedule meetings without guessing. DST-aware β uses current offsets from your system's zone database.
Use ToolPTO Accrual Calculator
Calculate how much PTO you've accrued, what's left after time off taken, and how much you'll have on a future date β given your annual PTO, start date, and as-of date.
Use ToolRectangle Area (Square Footage)
Compute the area and perimeter of a rectangular room, yard, or surface. Use for square footage from length Γ width.
Use ToolTriangle Area Calculator
Compute the area of a triangle from its base and perpendicular height.
Use ToolDrive Time / Travel Time
Estimate how long it takes to cover a distance at a given speed. Distance Γ· speed, plus optional stops.
Use ToolDiscount / Percent-Off Calculator
Compute the sale price, savings, and optional tax-inclusive total from an original price and a percent discount.
Use ToolRate Γ Time β Distance (walking / running / cycling totals)
Multiply a per-period rate by a duration to get total distance. Use for walking / running / cycling plans: "2.5 mi/day for 6 weeks".
Use ToolReading Pace Planner
Compute pages-per-day / pages-per-reading-session needed to finish a book by a target date.
Use ToolTax Scam Red-Flag Checker
Score an email, text, or phone call for common IRS-scam signals. Produces a 0β100 risk score with the specific red flags called out.
Use ToolCapsule Wardrobe Budget Planner
Allocate a clothing budget across category weights (tops / bottoms / layers / shoes / accessories / outerwear) for a style and season.
Use ToolDays Until Event Counter
Count down to a target date β wedding, vacation, exam, baby due, project deadline. Shows days, weeks, exact Y/M/D, and the weekday so you can plan around it.
Use ToolScience
Ohm's Law Solver
Given any two of voltage (V), current (A), and resistance (Ξ©), solve for the third. Also returns power (P = V Γ I).
Use Tool1D Kinematics Solver
Solve for any of initial velocity, final velocity, acceleration, time, or displacement given three of the others. Constant-acceleration equations of motion.
Use ToolCircle Solver
Given any ONE of radius, diameter, circumference, or area, compute the other three. Works in any consistent length unit (meters, feet, inches, etc.). Includes an interactive draggable visualizer.
Use ToolFFT Analyzer
Paste a time-domain signal (comma/newline separated samples) and a sample rate. Returns the magnitude spectrum, top 5 peak frequencies, and a visual plot.
Use ToolConductor Resistance
Resistance of a length of wire/cable given its material and cross-section. Uses R = ΟΒ·L/A with resistivity looked up from the materials database.
Use ToolLED Series Resistor
Calculate the series resistor for a single LED. Given supply voltage, LED forward voltage, and desired forward current, returns the required resistance, nearest E12 standard value, and recommended power rating.
Use ToolWire Voltage Drop
Calculate voltage drop over a 2-wire conductor given current, length, cross-section, and conductor material. Resistivity is pulled from our materials database with source attribution.
Use ToolAC Power Calculator
Single-phase and three-phase AC power calculator. Solve for current, apparent power (kVA), or real power (kW) using voltage and power factor.
Use ToolTransformer Turns Ratio Solver
Given any three of primary voltage, secondary voltage, primary turns, and secondary turns, solve the fourth using the ideal transformer ratio.
Use ToolBattery Runtime Estimator
Estimate battery backup runtime from battery voltage, amp-hours, battery count, usable depth of discharge, inverter efficiency, and continuous load.
Use ToolBattery Runtime Calculator (Wh / Watts)
Simple Wh-based battery runtime: given a battery in watt-hours and a load in watts, compute how long it will run. Use for portable power stations (Jackery, EcoFlow, Anker) and spec-sheet sizing.
Use ToolDownload / Upload Time Calculator
Estimate how long a file transfer will take based on file size and connection speed. Handles mixed units β file size in MB/GB/TB, speed in Mbps/Gbps/MB-per-second.
Use ToolInternet Speed Needs Estimator
Estimate the minimum download + upload Mbps your household needs from concurrent streams, video calls, gaming, cloud backup, and smart-home devices.
Use ToolProjector Throw Distance Calculator
Given a projector throw ratio (from the manufacturer spec sheet) and the target image width, compute the front-lens-to-screen distance. Supports a ratio range (min/max) when the projector has zoom.
Use ToolDisplay Size & Viewing Distance Planner
Given a display diagonal and aspect ratio, returns the SMPTE-recommended (30Β° FOV) and THX-recommended (36Β° FOV) viewing distances. Use these as the bounds for conference-room, classroom, or home-theatre seating design.
Use ToolAudio Delay Alignment Calculator
Given the physical distance between a main loudspeaker and a delay/fill speaker, computes the DSP delay needed to time-align them at the audience. Temperature-corrects the speed of sound when provided.
Use ToolSpeaker Coverage Spacing Calculator
For ceiling-speaker installations, computes the per-speaker coverage radius at listener ear height and the grid spacing needed for uniform coverage. Uses the manufacturer's specified coverage angle.
Use ToolRT60 Reverberation Estimator (Sabine)
Estimates reverberation time (RT60) for a room using the Sabine formula given room volume and total absorption. Accept either matched surfaces/coefficients arrays or a single total-absorption number.
Use ToolPoE Budget Calculator
Checks whether the active PoE endpoints on a switch fit within the switch's total PoE budget, accounting for IEEE 802.3af/at/bt class reservations and estimated cable loss.
Use ToolFiber Optic Loss Budget Calculator
Total optical link loss from fiber attenuation, connectors, and splices. Compared against a user-supplied link budget (Tx power β Rx sensitivity from the transceiver spec) to tell you whether the link is feasible.
Use ToolRack Power + Thermal Planner
Given equipment wattages in a rack, computes total planned load (with overhead), heat load in BTU/hr, AC cooling tonnage, and branch current at a given voltage / phase.
Use ToolPower Law Solver (P/V/I/R)
Solve for any of power, voltage, current, or resistance given any two of the others. Combines P = VΒ·I, P = IΒ²Β·R, P = VΒ²/R, and Ohm's law.
Use ToolVoltage Divider Calculator
Solve for any of Vin, Vout, R1, or R2 in an unloaded voltage divider. Standard formula Vout = Vin Γ R2 / (R1 + R2).
Use ToolRight Triangle Solver
Solve for any unknown sides or non-right angles of a right triangle given any two values. Uses the Pythagorean theorem and SOH-CAH-TOA. Includes an interactive draggable visualizer.
Use ToolFluid Pressure at Depth
Hydrostatic pressure at a given depth in a fluid. Solve for pressure, depth, or density. Density auto-resolves from a curated fluid library (water, seawater, mercury, oil, air) or accepts a custom value.
Use ToolEscape Velocity Calculator
Compute the escape velocity from any astronomical body, or solve for the body's mass or radius from a known escape velocity. Default body data comes from NASA fact sheets (Earth, Moon, Mars, Sun); supports custom bodies via mass + radius.
Use ToolOrbital Period Calculator
Kepler's Third Law solver: given a central body and a semi-major axis, compute the orbital period. Or solve for any of period / semi-major axis / central mass. NASA / IAU body data populated automatically.
Use ToolSurface Gravity Calculator
Compute the surface gravity of any body: g = GM/rΒ². Companion to the escape-velocity calculator. Solve for g, mass, or radius. NASA / IAU body data populated automatically.
Use ToolHeat Capacity & Temperature Rise
Compute the heat energy needed to raise (or lower) a material's temperature: Q = mΒ·cΒ·ΞT. Specific-heat lookup from a curated material table (water, seawater, oil, mercury, air, steel, aluminum, copper, concrete, glass, wood, ice).
Use ToolWork / Energy / Power Solver
Multi-mode mechanics solver for kinetic energy (Β½mvΒ²), potential energy (mgh), work (FΒ·dΒ·cosΞΈ), and power (W/t). Pick the relationship, leave one variable blank, fill the rest.
Use ToolProjectile Motion Solver (2D, no drag)
Two-dimensional projectile motion: given launch speed, angle, and height, compute time of flight, horizontal range, max height, and impact speed. Reverse mode solves for the launch angle that hits a given range.
Use ToolArc Length & Sector Area Solver
Given any TWO of {radius, central angle, arc length, sector area}, solve for the others. Also reports chord length and segment area. Includes an interactive draggable visualizer.
Use ToolCylinder / Sphere / Cone Solver
3D-primitive solver: pick the shape (cylinder / sphere / cone), pick the unknown (volume / surface area / radius / height), fill the rest. Reports lateral area + slant height where applicable.
Use ToolTriangle Solver (Full)
Solve any triangle given any three of {a, b, c, A, B, C} including SSS, SAS, ASA, AAS, and the ambiguous SSA case. Reports both solutions when SSA admits two valid triangles. Distinct from the right-triangle-solver (which assumes a 90Β° angle).
Use Tool