About Sensible Calculators

Sensible Calculators is a growing collection of free online calculators for the numbers people actually need day to day — how much concrete to order, what a loan will cost, how many grams are in a cup of flour, or how many days are left until a deadline.

Every calculator shows the formula it uses, so you can check the working and understand the result rather than just trusting a number. Calculations run entirely in your browser: the values you type are never sent to our servers.

Our standards

We use published, widely accepted formulas and exact conversion factors (for example, 1 inch = 2.54 cm by international definition). Where a result is an estimate — such as calorie needs or roasting times — we say so and explain the assumptions.

Found a mistake or want a new calculator? Get in touch.