About Us
Clear, accurate calculators for the numbers people deal with every day.
CalcFriendly is a free collection of online calculators for money, health, dates and school. We built it because we kept finding calculators that hid the math, buried the answer under pop-ups, or asked for an email address before showing a result. We wanted a set of tools that are fast, honest about how they work, and easy to use on a phone.
What we believe
- Show the working. Every calculator comes with a guide that explains the formula, walks through an example you can check by hand, and says where the result's limits are.
- Respect privacy. All calculations run in your browser. We don't collect or store the numbers you type.
- Keep it free. The site is supported by advertising, so the calculators stay free for everyone. Ads never change the results.
- Plain language. No jargon without an explanation.
How we check accuracy
Each calculator uses the standard, published method for its field: the amortization formula used by lenders, World Health Organization BMI categories, the Mifflin-St Jeor equation for energy needs, and the official definitions of imperial units in terms of metric ones. Before publishing, we test every calculator against worked examples calculated by hand. We review the guides regularly and update them when guidance changes.
What our calculators are not
Our results are estimates for general information and learning. They aren't financial, medical, legal or tax advice, and they don't replace a conversation with a qualified professional. Read our disclaimer for details.
Get in touch
Found a mistake, or want to suggest a new calculator? We read every message. Contact us.