All Calculators
84 free calculators, organized into 17 categories below. Every one runs entirely in your browser, shows the formula it uses, and includes a worked example — pick a category to see the calculators in it.
Math
4 calculators
Everyday and school-level math tools — fractions, factors, percentages, and quick arithmetic you'd otherwise reach for a calculator app to do.
Finance
16 calculators
Loans, interest, tax, and investment growth calculators for planning purchases, EMIs, and savings.
India
3 calculators
Calculators built around Indian tax and employment rules: income tax (old vs new regime), HRA exemption and gratuity.
Health & Fitness
3 calculators
General wellness estimators for body measurements and daily energy needs — not a substitute for medical advice.
Date & Time
2 calculators
Work out the gap between two dates, someone's exact age, or add and subtract durations of time.
Unit Conversion
19 calculators
Convert between common units of length, weight, temperature, volume, area, and speed.
Geometry
3 calculators
Area, perimeter, and volume for common 2D and 3D shapes, with the formula shown for each.
Statistics & Probability
2 calculators
Summarise a data set or work out the odds of simple events, with the underlying method explained.
Scientific
2 calculators
Trigonometric, logarithmic, exponential, and other scientific functions for coursework, homework, and quick technical calculations.
Physics
3 calculators
Core physics and electronics relationships — speed, distance, time, and basic circuit calculations.
Chemistry
2 calculators
Solution concentration and quantity calculations for chemistry coursework.
Education & Grades
2 calculators
GPA and grade planning tools for students.
Business
3 calculators
Margin, markup, and break-even calculations for pricing and small-business planning.
Construction & Home
11 calculators
Material-quantity estimators for home improvement and construction: paint, tiles and flooring, concrete, bricks, plaster, roofing, rebar, stairs and water tanks.
Vehicle & Fuel
4 calculators
Fuel cost, fuel economy, EV charging cost and tyre size calculators for planning trips and comparing vehicles.
Everyday
3 calculators
Quick calculators for common daily situations like discounts, tipping and comparing unit prices.
Fun
2 calculators
Light, just-for-entertainment calculators. Not scientific — for fun only.
Not sure where to start? The FAQ page covers common questions about accuracy and privacy, or suggest a calculator we don't have yet.