In a jam? Free calculators with the work shown.
Every calculator here gives you the number and the arithmetic that produced it. No sign-ups, no lead forms, no email capture. No answer you have to take on faith.
(90 − 88 × 0.75) ÷ 0.25 = 96
Skip the final entirely and you finish the course at 66%.
Four calculators, and what each one shows you
- Percentage What is 15% of 80? And every other way of asking it. 80 × 15 ÷ 100 = 12
- Tip The tip, the total, and what each person owes to the cent. $84.20 × 20% = $16.84
- Final grade What you need on the final, and where you land if you skip it. (90 − 88 × 0.75) ÷ 0.25 = 96
- Age Exact age in years, months and days. Leap-day birthdays handled. borrow from the prior month
Also from CalculatorJam: the Maintenance Calorie Calculator, which shows maintenance calories as a range across three published equations.
What each calculator covers
The percentage calculator handles every common way of asking the question: a percent of a number, what percent one number is of another, the number a percentage came from, and percentage increase, decrease and difference. Each result shows the formula with your numbers in it.
The tip calculator works out the tip and the total, then splits the bill. Per-person shares round up to the cent, so the group always covers the bill, and you can tip on the amount before tax.
The final grade calculator finds the score you need on a final to reach a target grade, says plainly when that score is above 100%, and shows where you finish if you skip the final. A weighted-grade tool handles courses graded by category.
The age calculator gives exact age in years, months and days, and the total days lived. It states how it handles month ends, and counts a February 29 birthday as March 1 in common years.
Why the work is shown
A number on its own is something you have to trust. A number with its arithmetic beside it is something you can check, and correct if we have it wrong. Every page states the formula it uses, the limits it accepts, the conventions it follows where maths allows more than one, and the date it was last updated.
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