Why I started LeoCalculator
I am Vamshi Krishna, and I build websites. LeoCalculator started because I got tired of the same problem every time I needed a calculator.
I would search for something simple — a compound interest tool, a sample size calculator, an aspect ratio helper — and land on a page that gave me one number and nothing else. No formula. No explanation of what it actually calculated. No way to check the arithmetic by hand. Some of them asked me to sign up before showing a result. Others buried the actual calculator under three screens of filler text that nobody reads.
What bothered me most was how confident those pages looked while telling me almost nothing. A number without context is not an answer. It is a guess with a font on it.
So I started building my own. First one calculator, then a few more, then a proper site once it became clear that other people wanted the same thing.
What I actually care about when building a calculator
I am a web designer first. Most of what makes LeoCalculator look and feel the way it does comes from specific things I disliked about existing tools.
- Show the formula. Every calculator page explains how the result is produced. If you cannot verify the math yourself, you are trusting a black box, and I do not think that is a fair trade.
- Show the working figures. Not just the final number. The inputs, the intermediate values, the tax bracket breakdown, the sample size before rounding up. The full picture, not a headline.
- State the assumptions. A mortgage calculator that silently assumes a 30-year term at 6% is not being helpful — it is hiding its choices. Every assumption should be visible and editable.
- Let you work in both directions. A sample size calculator should also solve backward from a given sample to a margin of error. A BMI tool should answer "what weight puts me at a BMI of 22?", not only "what is my BMI?".
- Explain the limits. Every calculator has a section on what it does not model. A tax estimator is not tax software. A BMI calculator is not a medical diagnosis. Saying that plainly is more useful than pretending the tool is more than it is.
- No accounts, no email walls, no upsells. Most of the tools run entirely in your browser. I do not need to know who you are to tell you what 7.75 hours is in decimal hours.
Did LeoCalculator raise money?
No. There is no outside funding. No venture capital, no angel investors, no partner firm. It is just me.
That was a deliberate choice, and it shaped almost everything about how the site works. When a calculator site is funded, the pressure is to grow fast: more pages, more ads, more pop-ups, more emphasis on traffic than on accuracy. I would rather have a small number of calculators that are actually correct than a thousand pages of half-explained numbers.
Being independent also means I can say no. I can turn down ad networks that want intrusive pop-ups on every page. I can keep a calculator online even if it does not bring in traffic, because a small group of people use it heavily. I can slow down and rewrite an explanation that is not clear. None of that is possible if the site has to hit a growth target every quarter.
It also means I cannot move as fast as a funded competitor. I build things when I can, with the hours I have. Some calculators took months longer than I wanted. There is a list of tools people have asked me for that I have not gotten to yet. That is the trade-off, and I would make it again.
What the site earns, and where it goes
The site earns from advertising and from the calculators themselves. That money goes back into three things:
- Building new calculators. Each one takes research, careful implementation, testing against known values, and writing the explanation that goes with it. A good calculator takes days, not hours.
- Keeping existing ones accurate. Tax brackets change every year. Statistical conventions evolve. I update the calculators when the rules underneath them change.
- Hosting and infrastructure. The tools run in the browser, but the pages still have to load quickly and reliably for everyone who visits.
There is no growth team, no sales department, no support ticket queue. It is one person who likes building calculators and designing clean interfaces, trying to build good ones.
What this means for you
A few practical things:
- The tools are free and will stay free. There is no paywall planned.
- No dark patterns. No "unlock the full result" screens, no forced sign-ups, no silent email subscriptions.
- Your inputs stay with you. Most calculators run entirely in the browser, so the numbers you type do not leave your device.
- Corrections are welcome. If a formula is wrong or an explanation is unclear, I want to hear about it. A calculator that is confidently wrong is worse than no calculator at all.
Where this is going
More calculators. Better explanations. Better mobile layouts. Better handling of currency, unit conversion, and shared results between tools. And eventually, the less-common calculators that no one else builds because they are not flashy enough to attract ad revenue.
The list of things to build is long. I am working through it at the pace one person can manage. Slower than I would like, faster than I expected when I started.
Get in touch
If there is a calculator you would like to see added, or one on the site that could be clearer, send me a note. I read everything. A good number of the tools on this site exist because someone asked.