Speed Calculator
Solve speed, distance or time and convert between speed units.
Calculators
Everyday maths, money and measurements, worked out for you.
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Probability Calculator
Single and combined event probability, odds and repeated trials.
Scientific Notation Calculator
Convert to and from scientific, E and engineering notation.
Lean Body Mass Calculator
Lean mass and fat mass from measurements or body fat.
Time Duration Calculator
The time between two moments, in every unit.
Big Number Calculator
Exact arithmetic on numbers of any size, using BigInt.
Square Footage Calculator
Area of a room in square feet, metres or yards.
401k Calculator
Projected balance with employer match and contribution limits.
Basic Calculator
A full keypad calculator with memory keys and a running tape.
Social Security Calculator
How your benefit changes with the age you claim.
Hours Calculator
Count the hours between a start and end time, breaks deducted.
Income Tax Calculator
Estimate tax across progressive bands with your own rates.
Pace Calculator
Solve pace, time or distance for running, cycling, swimming or walking.
Percentage Change Calculator
Increase, decrease and the difference between two numbers.
Number Base Calculator
Convert a number between any two bases from 2 to 36.
GFR Calculator
Estimated GFR by CKD-EPI 2021, MDRD and Cockcroft-Gault.
Ohms Law Calculator
Solve for volts, amps, ohms or watts from any two.
SIP Calculator
Project a systematic investment plan with monthly contributions.
Percentage Calculator
Work out percentages, percentage change and reverse percentages.
Bond Calculator
Bond price, current yield and yield to maturity.
BAC Calculator
Blood alcohol estimate by the Widmark formula, over time.
Salary Calculator
Convert pay between hourly, daily, weekly, monthly and annual.
Volume Calculator
Volume of any 3D shape and conversion between volume units.
TDEE Calculator
Total daily energy expenditure across every activity level.
Repayment Calculator
How long a debt takes to clear at the payment you can make.
Roofing Calculator
Roof area, squares and bundles from pitch and footprint.
Resistor Calculator
Colour codes both ways, plus series and parallel values.
Dice Roller
Roll any dice notation, with modifiers and statistics.
Day Counter
Days between dates, with or without weekends and holidays.
Logarithm Calculator
Log to any base, natural log and antilog, with the change of base shown.
BMI Calculator
Calculate body mass index in metric or imperial units.
Amortization Calculator
Every payment split into principal and interest, with totals.
Mortgage Calculator
Monthly mortgage payment with tax, insurance and total interest.
Factor Calculator
Every factor of a number, in pairs, with prime factors marked.
Least Common Multiple Calculator
LCM by prime factorisation, listing and the GCF shortcut.
Molarity Calculator
Molarity, moles, mass or volume, plus dilutions.
Triangle Calculator
Solve any triangle from three known sides or angles.
Standard Deviation Calculator
Sample and population standard deviation with every step shown.
Mileage Calculator
Mileage reimbursement and the real cost of a trip.
Depreciation Calculator
Straight line, declining balance and sum-of-years schedules.
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About these calculators
A full set of calculators for the numbers that come up in real life. Work out loan and mortgage repayments with a full amortisation schedule, add or strip VAT and GST, price a job by margin or markup, and find the break-even point for a product. Convert between any units, solve triangles and circles, and run descriptive statistics over a data set.
There are calculators for the everyday too: percentages and percentage change, tips and discounts, dates and durations, pace and fuel cost, and health estimates including BMI, BMR, TDEE and daily calories. Every one shows the formula it used rather than just an answer, and every one runs entirely in your browser, so nothing you enter is ever uploaded.