Calculators that just work

Fast, no-nonsense tools for carpenters, painters, bricklayers, roofers and DIYers. Estimate materials and costs in seconds.

Percentages, geometry, algebra and trigonometry made effortless, with the formulas explained.

Convert length, weight, temperature, speed, data and number systems between any units.

Loans, investments, savings and business metrics — plan your money with confidence.

Body, diet and fitness estimates. Informational only — not medical advice.

Motion, force, energy, electricity and heat — solved with the equations shown.

Averages, spread, probability and odds — make sense of your numbers.

Time, dates, home and transport tools for daily life.

Cooking conversions, party planning and baking math.

Footprints and renewable energy — go a little greener.

Tools for gardeners, farmers, pet owners and life-science enthusiasts.

Concentrations, moles and solutions, with the chemistry explained.

Pace, calories and performance for athletes of every level.

Education, tech and just-for-fun calculators that don't fit anywhere else.