Engineering my own healthspan in public.
I'm Aayush — a software engineer who got obsessed with longevity research, started measuring everything, and turned the spreadsheets into the calculators on this site. Aayushnitya is where I publish the tools I use on myself and the guides I wish had existed when I started.
What Aayushnitya is.
A small, independent publication on healthspan optimization. It is not a clinic, a coaching service, or a supplement brand. There are no affiliate links on the calculators.
The site has three parts: free calculators that take a single input set and return a single useful number; paid PDF guides that compile field-tested protocols on specific problems (high-protein eating, cortisol regulation, fitness tracking); and a weekly research drop with one new thing I tested or learned.
Everything is built to be read once and re-used forever. No account walls. No drip funnels disguised as content.
Editorial principles.
Measure first, intervene second.
Every protocol on this site comes after a baseline measurement. If a metric does not move, the protocol gets cut. Quantified self is not a hobby — it is the test bench.
Cite the source.
Formulas behind the calculators are peer-reviewed: Mifflin–St Jeor for resting metabolic rate, US Navy method for body fat, Karvonen for Zone 2 heart rate, biomarker-weighted estimators for biological age. Where the science is contested, that is stated up front.
Minimal software, durable output.
Tools are single-purpose calculators that prerender to static HTML. No accounts. No tracking pixels on the calculation. The PDFs you buy work offline forever.
Honest about what is not known.
Biological age is an estimate, not a diagnosis. Peptide dosing is informational, not medical advice. The site flags speculation explicitly and points to gaps in the evidence base when relevant.
What I personally track.
Every calculator on this site exists because I was already measuring the underlying metric on myself. If I don't track it, I don't publish a tool for it.
- ·Resting heart rate, HRV, sleep architecture (wearable, daily).
- ·Body weight, body fat, waist-to-height (weekly).
- ·Protein intake, total calories, fasting window (daily food log).
- ·Zone 2 minutes per week and VO2 max trajectory (monthly).
- ·Annual bloodwork: lipid panel, HbA1c, fasting insulin, ApoB, hs-CRP, vitamin D, ferritin.
Disclosure & medical disclaimer.
I am not a licensed physician, dietitian, or medical professional. Nothing on this site is medical advice. The calculators are educational estimates, not diagnostics. The PDF guides describe protocols I have used on myself or compiled from peer-reviewed sources — they are starting points for discussion with your own clinician, not prescriptions.
If a tool or guide could plausibly interact with a medication or a clinical condition (peptide dosing, prolonged fasting, restrictive macros), the relevant page says so.
Revenue comes from the paid PDF guides on Gumroad. There are no affiliate links on the calculator pages and no sponsored content in the newsletter.
Get the weekly drop.
One thing I tested, learned, or shipped — every week. Plus a free PDF.