Free calculators that just work
Quick, clear answers for home projects, pay and selling fees. Every calculator shows its formula and a worked example, so you can see where the number comes from.
Every formula is tested, and every fee or tax rule links to its official source. How we calculate · About CalcHandy
Most used calculators
Home & DIY
View allMaterials, sizing and coverage for projects around the house.
Tons and cubic yards for paths and drivewaysMulch Calculator
Cubic yards and bags of mulch for bedsDeck Stain Calculator
Gallons of stain for any deckBTU Calculator
Air conditioner size for any roomWire Gauge Calculator
Copper AWG by amps, distance and voltage dropGenerator Size Calculator
Watts needed with surge and headroom
Pay & Work
View allOvertime, time off, shift pay and tips, worked out the way payroll does it.
Overtime pay at 1.5x, 2x or custom ratesPTO Accrual Calculator
Accrued paid time off and balanceShift Differential Calculator
Night and weekend premium payTip Pool Calculator
Split tips by hours and weightNo Tax on Tips Calculator
Federal tips deduction and tax savedNo Tax on Overtime Calculator
Deduction, tax saved and take-home per overtime hour
Seller Fees
View allSee exactly what a marketplace or payment processor takes, and what you keep.
Pets
View allSize, feed and tank estimates for dogs, backyard chickens and fish.
Instant answers
Results update as you type. No sign-up, no waiting.
Formulas shown
Every page explains the math with a worked example.
Dated source checks
Fee and tax pages link to the official source and show the date we last checked it.
How CalcHandy works
Type your numbers and the answer updates instantly. Nothing is sent to a server, and there is nothing to sign up for. Below each calculator you will find the formula, a worked example with real numbers, a reference table and answers to common questions.
Accurate and up to date
Each formula is tested against known answers before it goes live. Electrical and tax tools use published sources such as the NEC and the IRS. Fee calculators show the date we last checked the platform's official rates, because marketplaces change their pricing often. Always confirm important numbers with the official source or a professional.
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