CalcRipple is a collection of free online calculators. Each page puts the calculator first, then explains how the result is worked out, with the formula, worked examples and answers to common questions.
What you will find on each page
- A calculator that works in your browser, on a phone or a computer.
- The formula written out in plain words, so you can check the result by hand.
- Worked examples with the answers shown.
- Notes on what the calculator does not cover, such as rules that differ between schools.
- Links to the sources the page relies on, and to related calculators.
How the calculators are checked
Before a calculator goes live, its calculation code is tested against worked examples. The expected answers are computed a second time, separately, in a different tool, and the two results have to match. Where exact decimals matter, such as percentages and rounding at a grade cutoff, the calculators use exact arithmetic instead of floating point numbers, so a score just under a cutoff is not rounded up into a better grade.
Privacy
Calculations run in your browser. The numbers you type are not sent to CalcRipple. The Last used calculators list on the home page is saved in your own browser storage and stays on your device.
Who maintains CalcRipple
CalcRipple is created and maintained by Dennis Norton. Each calculator page shows the date it was last updated.
Good to know
Results are for information and learning. Rules such as grading scales differ between schools and instructors, so check the rules that apply to you before relying on a result.