Finance
Unit Conversion
Date & Time
Construction
Trades
Health
Whether you're crunching numbers for a big life decision or just need a quick conversion, CalcBuddy has a free online calculator ready for you — no sign-up, no account, no nonsense.
The house affordability calculator helps you figure out what's within your budget, and the rent vs. buy calculator breaks down the true long-term cost of each option so you can make the most informed housing decision of your life.
The mortgage calculator shows your full monthly payment including taxes and insurance. The loan payoff calculator handles personal loans and auto financing. For the long game, the compound interest calculator shows how your savings or debt grows over time — and it's eye-opening either way.
The retirement calculator helps you map out how much you need to save, how long your money will last, and when you can finally stop setting an alarm. Combine it with our savings goal calculator and credit card payoff tool to build a full financial picture.
Start with the BMI calculator to understand your body mass index, then head to the TDEE calculator to find out exactly how many calories your body burns each day. Whether you're managing macros, tracking water intake, or planning a pregnancy, the due date calculator, ovulation calculator, and macro calculator have you covered.
The unit converter and conversion tools on CalcBuddy handle length, weight, temperature, volume, speed, and more — metric to imperial and back again in seconds. No fumbling with formulas.
From the everyday (age calculator, days between dates) to the technical (Ohm's Law, pipe flow, concrete calculator), CalcBuddy is the one bookmark you'll actually use. Fast, accurate, and built for real people doing real math.
I didn't build CalcBuddy to change the world.
But I did want to build something. For as long as I can remember, I wanted a project of my own, something useful, something I could point to and say I made that. Not just for the income potential, though that mattered too. More than that, I wanted to create something that quietly helped people in small but real ways, every single day.
Calculators felt right. Everyone needs them. And most of the ones online are cluttered, slow, or buried under ads you can't close. So I built the site I would want to use myself.
If you are here, it's probably because you have a number you need to figure out. Maybe it's a mortgage. Maybe it's a loan, a retirement target, or just how many calories you burned. Whatever it is, I hope CalcBuddy gives you the clear answer you came for.
That's the whole idea.