Math calculators
Percentages, percentage change, averages, discounts, tips, unit prices and ratios — solve for the value you are missing and see the formula and every step.
Everyday arithmetic, solved in whichever direction you need. Give the values you know and the calculator finds the one you are missing, then shows the identity it used and your numbers substituted into it.
Percentages cause more mistakes than any other everyday sum, usually because the base is unclear. Each calculator here names the value it measures against, so a 25% rise and a 20% fall are never confused.
Start with a question
Questions people arrive with, and the calculator that answers each one.
- What is 15% of 200?Percentage — “Find a percent” →
- 30 is what percent of 200?Percentage — “Find the percentage” →
- What is the percentage increase from 80 to 100?Percentage change →
- What is 20% off and then another 10% off?Discount — stacked discounts →
- How much does each person pay with an 18% tip?Tip — split the bill →
- What is the average of 72, 85, 90, 68 and 85?Average — mean and median →
- Is 1 kg for 5.99 cheaper than 500 g for 3.49?Unit price — compare two packs →
- How tall is a 16:9 image that is 1920 wide?Aspect ratio — solve height →