Free percentage calculator.
Make it add up.
Find a percentage, percentage change or an original amount. Work out discounts, tax and shared bills with a free percentage calculator that runs in your browser.
Let’s work it out.
Type or tap. Enter calculates. Decimal comma works too; use ; between function arguments, like min(2; 8).
How percentages & scientific functions work
With Smart % on, 200 + 10% = 220 and 200 − 10% = 180. Turn it off to treat 10% as 0.1 in every expression. Multiplication always treats 10% as 0.1.
Use DEG for angles in degrees and RAD for radians. Supports powers, roots, factorials, trigonometry, logarithms and constants π and e. Use parentheses to make your intended order clear. Results are rounded for display.
Percentages, plans & money.
Work out a change, share a bill or explore a savings goal. No account, no spreadsheet required.
Percentage calculator
Bill, discount & tax
Loan payment estimate
Savings explorer
For estimates and learning. Check rates, fees and terms with your provider before making a financial decision.
Same quantity. Different unit.
Convert everyday measurements, from centimetres and miles to temperature, data and speed.
Unit converter
Put your dates in order.
Count calendar days or move a date forwards and backwards. Dates are handled as calendar dates, without time zones.
Days between dates
Add or subtract time
Make a tricky number click.
Fractions, statistics, equations and number bases. Useful little helpers, with the important details kept visible.
Fractions
Statistics
Quadratic equation
Two equations, two unknowns
Number base converter
Give your function a little space.
Plot a real-valued function of x. Explore the view, compare a few points or download your graph.
A few points on the curve
| x | f(x) |
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How to use this percentage calculator
To find 20% of 150, choose “What is A% of B?”, enter 20 and 150, then calculate: the answer is 30. To measure a change from 80 to 100, choose percentage change: the increase is 25%. A percentage change uses the starting amount as its base; a zero starting amount has no defined percentage change.
The bill helper applies a discount first, then calculates both tax and tip on the discounted amount. For an 80 bill, a 10% tip and two people, the shared total is 88 and each person pays 44. Check how a restaurant or local tax rule handles tips and rounding before using an estimate for a payment.
What else can I calculate?
Use the workspace tabs for scientific expressions, percentages and money, 13 unit groups, calendar dates, fractions, statistics, quadratic equations, two-variable linear systems and base conversion. The graph tab plots a real-valued function of x and exports the visible graph as a PNG. Mathematical results use bounded precision and are rounded for display.
Your expressions and working notes stay in this tab. No account, calculation uploads or advertising scripts in this workspace. Closing or reloading clears the notes. Sources & credits · Privacy