Math & Conversion Calculators

Not every calculation requires a spreadsheet. Our everyday math tools handle the quick, practical questions that come up constantly — splitting a restaurant bill, calculating a discount percentage, converting between units, figuring out a tip for a group, or working out what percentage one number is of another.

These tools use standard arithmetic formulas with no special assumptions or model inputs. Percentage calculations follow the basic formula: Part/Whole × 100. Tip calculations divide the bill and distribute tip amounts per person. Age calculations count from a birth date to the current date using calendar arithmetic.

Use these for quick, on-the-spot answers. While the math is straightforward, always double-check important financial figures — especially when splitting shared expenses or calculating sales tax — as rounding methods can produce slightly different results depending on the order of operations.