About
A small, growing portfolio of free health calculators that skip the motivational fluff and give you the number the math actually produces — even when it's not the one you wanted.
BluntCalc isn't one app — it's a family of single-purpose calculators, each built around one uncomfortable but useful number: how long weight loss will realistically take, whether your waist size puts you at metabolic risk, what your smoking habit has actually cost you.
Most tools run entirely in your browser. No account, no signup, no data sent anywhere for the core calculation. Each one is built by one person, tested against peer-reviewed research where research exists, and shipped free because paywalling a formula felt wrong.
HonestSlim, InResRisk, and SmokeLoss are the first three. BluntCalc is designed to grow into a portfolio of small, focused tools — each one solving a single problem well instead of trying to solve everything.
The Portfolio
BluntCalc is the hub. Each calculator underneath it gets its own dedicated site, free to go deep on one topic instead of competing for space on a crowded homepage.
BluntCalc ├── HonestSlim — realistic weight-loss forecasting ├── InResRisk — insulin resistance screening ├── SmokeLoss — smoking cost calculator └── Future tools — more uncomfortable truths, coming soon
Current Projects
Monte Carlo weight-loss forecasting — a realistic range instead of one fake date.
VISIT HONESTSLIM →Insulin resistance and metabolic risk screening from waist and height alone.
VISIT INRESRISK →What a smoking habit actually costs, converted into cars, houses, and years.
VISIT SMOKELOSS →Mission
Most health apps are optimized to keep you feeling good, not to keep you informed. They show you a flattering number, a hopeful date, a green checkmark — because motivation sells better than math.
BluntCalc exists to do the opposite: run the actual numbers, show the actual range of outcomes, and let you decide what to do with an honest answer. Not because bad news is more virtuous than good news — but because you can only act on the truth if someone shows it to you.
The goal isn't to depress you. It's to get you the uncomfortable number early enough that it's still useful — not five years later, as a diagnosis.
Philosophy
Every calculation is built on a named formula, not a vibe — Mifflin-St Jeor, waist-to-height ratio, Body Roundness Index. If a number can't be traced back to a source, it doesn't ship.
"You'll lose it by March 14th" is a fantasy dressed up as a fact. Where the underlying reality is uncertain, the tool shows a range or a risk zone instead of one dishonest number.
No "you've got this!" banners. No confetti for a normal BMI. You're an adult who came here for a number, not a pep talk — you'll get the number.
Every calculation runs client-side, in your browser. No account, no server-side storage of what you enter, no ad-tech tracking beyond anonymous page analytics.
These tools flag risk from measurements you can take at home. They don't replace a blood test, a scan, or a doctor. Blunt doesn't mean reckless — every tool says plainly what it can't tell you.
The core calculator on every tool is free, forever, with no signup wall in front of the honest number. That's the whole point of building it.
The Promise
Every calculator published under the BluntCalc name has to satisfy four rules before it ships. No exceptions for a tool that would look better without them.
No invented math. If a peer-reviewed formula exists for the thing being measured, that's what ships.
Ranges and risk zones where the underlying reality is uncertain — never a single fake number dressed up as precision.
No signup wall, no paywall, in front of the honest number. Every core calculator stays free.
No confetti for a mediocre result. No softened wording to keep you on the page. The number wins over the vibe, every time.
Who's behind it
I'm Péter Wolf — online, Wolfy82. The "82" isn't decoration; it's my birth year. So no, BluntCalc isn't a weekend project from a 22-year-old who's never had to actually apply any of this to their own body.
I wrote my first program in 1993 — yes, last century. These days that experience means two decades in the medical device industry, building software for FDA submissions in a field where "ship it and see what happens" isn't a strategy, it's a violation. Where a wrong number in a spec gets flagged, audited, and traced straight back to you. That's exactly why sloppy, feel-good health calculators bother me: I've spent most of my career in an industry that treats claims about the human body as something you have to prove, not something you get to guess at.
And here's the blunt part, since bluntness is the whole brand: I'm one of the people these tools are for. I've been fat — not "a few pounds before summer" fat, but fat as a kid, fat through my MSc in Computer Science, fat through every year of a desk job since. I'm not writing these tools from the outside, handing down advice about a problem I've never had. Building BluntCalc is part of how I'm finally doing something about it.
One more blunt admission: I use AI to accelerate development on BluntCalc. It's not because I can't write this myself — 30-odd years of doing exactly that says otherwise — it's because AI lets a solo developer ship a portfolio of tools far faster than working alone, and because learning to actually use AI well in real software development is a skill I'd rather build hands-on than read hot takes about. But speed doesn't get a pass on rigor: every formula, every calculation, and every scientific claim in a BluntCalc tool is checked against its source and reviewed by me before it ships — the same discipline 20 years in a regulated industry drilled into me, applied to a side project instead of a submission.
So each tool gets built the way I'd want it built if my own health depended on trusting the output — because it does. Real formulas, real citations, real ranges instead of fake certainty, shipped for free. If a BluntCalc tool told you something you didn't want to hear, and you did something useful with it — that's the whole point. I'm running my own numbers through these too.
Architecture
Every BluntCalc calculator gets its own dedicated home instead of living as one feature among dozens on a single crowded site.
HonestSlim focuses entirely on realistic weight-loss forecasting. InResRisk focuses entirely on metabolic health and insulin resistance. SmokeLoss focuses entirely on the true cost of smoking. Each one is free to go deep on its own topic, cite its own research, and build its own authority — rather than getting diluted as one tab in a bloated "all-in-one" health app.
BluntCalc brings them together under one roof and one philosophy: honest numbers, honest tools, no BS.
"THE TRUTH DOESN'T DEMOTIVATE YOU. FINDING OUT TOO LATE DOES."
— BLUNTCALC MANIFESTO