About
Handy Calc is a small collection of free calculators for everyday niche questions: how many grams are in a cup of flour, what Gas Mark 4 is in Fahrenheit, how much paint a room needs, how much yarn a blanket takes and how many days are between two dates.
Who maintains this site
The site is maintained by a small Editorial team. We do not claim professional credentials such as chef, contractor or certified fiber-arts qualifications.
How we build calculators
- Every calculator is a plain formula that runs in your browser. Nothing you type is sent to a server.
- Reference values (for example ingredient weights) come from named, linked sources listed on each page.
- Each calculator has automated tests that compare results with at least five known answers.
- Each page shows the formula, a worked example, its assumptions and limitations.
Use of AI
We use AI tools (large language models) to help draft page text and code. AI output is never published unchecked: numbers and formulas are verified against the cited sources and by tests. Read more in our editorial policy.