Free date calculator.
Make time add up.
Calculate days between two dates, count weekdays or add days, months and years. Free calendar date calculator with leap-year and month-end handling.
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) |
|---|
How to use this date calculator
Choose a start and end date to count the calendar days between them. From 28 February 2024 to 1 March 2024 there are two days, because 2024 is a leap year. Include the end date when both endpoint dates should count. Weekdays count Monday through Friday; local public holidays are not subtracted.
Add or subtract days, months or years in the second helper. Month changes keep the day where possible and clamp it to the last valid day otherwise: adding one month to 31 January 2024 gives 29 February 2024. These are calendar dates without times or time zones, so daylight-saving changes do not add or remove a calendar day.
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