Math tools
11 free math tools · Percentages, units and numbers
Work with percentages, fractions, ratios and number lists, or convert between units and number bases. Use the worked examples to check your inputs and understand the result.
All math tools
- Percentage calculator Percentage change, apply % to a value, margin & markup.
- Unit converter Length, mass, volume, temperature conversions.
- Fraction calculator Exact fraction arithmetic, simplified, with mixed numbers.
- Average calculator Mean, median, mode, range, deviation and quartiles.
- Ratio calculator Simplify a ratio, see shares, and solve a : b = c : x.
- Number base converter Convert between binary, octal, decimal, hex and base 36.
- Roman numeral converter Numbers to Roman numerals and back, with validation.
- GCD & LCM calculator Greatest common divisor and lowest common multiple.
- Quadratic equation solver Solve ax² + bx + c = 0, including complex roots.
- Scientific notation converter Convert to scientific and engineering notation.
- Grade & final exam calculator Work out your grade, or the exam score you need to hit a target.
Guides
- Percent vs percentage points, with examples A rise from 2% to 3% is one percentage point and a 50% relative increase. Learn the difference and avoid common percentage and discount mistakes.
- Weighted grades and final-exam scores: worked examples Calculate points-based and weighted grades, distinguish ungraded work from zero scores and find a required final-exam mark with clear assumptions.
- Ounces vs fluid ounces: weight and volume explained Understand the difference between oz and fl oz, choose US or imperial fluid ounces, and use ingredient density when converting between mass and volume.
- MB vs MiB: why storage sizes look different Compare decimal MB and GB with binary MiB and GiB. Work through a 1 TB example and separate unit differences from space used by formatting and software.