Your input stays in the browser
Current tools do their work in your browser. The balances, measurements, health inputs, and pasted text you enter are not sent to a server for calculation.
Free calculators that run in your browser
About Tools by Leaf
A growing collection of focused calculators and everyday utilities, built to load quickly, work on any device, and explain the answer.
Meet Leaf
Tools by Leaf is named after Leaf, the owner's corgi. Maple leaves are Leaf's symbol, which is why warm orange and red maple tones run through the site's artwork, while the working interface stays evergreen.
The illustrations add personality; they do not calculate, review, or endorse results. The working parts of the site stay calm, clear, and professional.
What you can expect
The limits are part of the answer
A useful result needs context. Tools explain their assumptions, rounding, and important limitations instead of presenting a number as more certain than it is.
Useful on a phone or a desktop
Pages are built to remain fast, keyboard-friendly, readable in light or dark mode, and usable on a narrow screen without an account or download.
One catalogue, many everyday jobs
The catalogue covers Home & DIY, Finance, Automotive, Health & Fitness, Travel, Pets, Kitchen, Work, Education, and Utilities. New tools are added carefully, with the same focus on clear assumptions, useful explanations, and accessible controls.
Questions or feedback? Visit the Contact page.