Money, tax & investing
Loans, interest, inflation, salary, tax and valuation results ignore many fees, local rules and changing rates. Speak to a licensed adviser, accountant or tax professional before deciding.
DISCLAIMER
Great for understanding. Not a substitute for a professional.
Lay Math explains the math behind everyday decisions. It doesn’t know your full situation — so treat every result as a well-reasoned estimate.
Last updated 11 October 2026
General
All results come from the figures you enter and the simplified formulas shown in “Show me why”. Starting figures are illustrative examples only. Lay Math is not responsible for decisions made using its results.
Health & medicine
BMI, steps and dose-by-weight are for understanding the math only. Never use them to choose a medicine dose — always follow your doctor, pharmacist, or the product label.
Safety & driving
Stopping distances, following gaps and ladder angles are idealised minimums. Real conditions — vehicle, tyres, weather, fatigue — can make them much worse.
Building & trades
Area, concrete, materials and mixing results are estimates. Follow manufacturer instructions, product safety sheets, and local building codes.
Sizes & conversions
Clothing and shoe sizes are averages; brands differ. Currency results use the rate you type, not a live market rate.
Learn more
See the Terms of use and the Help centre.