About FitCalc

FitCalc is a set of training and nutrition calculators built by a certified coach who uses them with real clients. Every tool here exists because the question came up often enough in coaching to be worth automating.

Who writes this

I'm Coach Ohm. I coach online from Bangkok through FitActo, working mainly with people who have full-time jobs and limited time to train.

I spent five years studying nutrition and training properly, certified through ISSA and PESA, and I still race triathlon myself. Every calculator on this site is built the same way I coach: it defaults toward a rate you can actually hold, not the fastest number it could show you — because the fast number is the one people end up abandoning.

Certifications

These are the real ones, and I can show the certificates for all of them.

ISSA — Certified Personal Trainer · Nutrition Coach · Corrective Exercise Specialist · Strength & Conditioning
PESA — Nutrition for Fat Loss · Endurance Sport Nutrition · Strength for Distance Runners · Practical Personal Trainer · The Science and Art of Muscle Hypertrophy · Fat-loss Specialist for Women
Other — Dry Sports Massage Fundamental

The certificates themselves

Certificate: PESA — Strength for Distance Runners — PESA — Strength for Distance Runners

Certificate: Dry Sports Massage — Fundamental — Dry Sports Massage — Fundamental

Certificate: PESA — Practical Personal Trainer — PESA — Practical Personal Trainer

Certificate: PESA — Science and Art of Muscle Hypertrophy — PESA — Science and Art of Muscle Hypertrophy

Certificate: PESA — Fat-loss Specialist for Women — PESA — Fat-loss Specialist for Women

Certifications not pictured above are available on request.

They are shown here for the same reason the rest of this page exists: a site giving people advice about their bodies should be able to show you who is giving it.

The rules this site follows

There is a specific reason to state these. A great deal of fitness content online invents its authority — made-up reviewing doctors, statistics attributed to research that is never named, "data from our users" from sites that collect no data. It is worth being explicit that this site does not do that.

Every number in a calculator is a published equation or an accepted range. Mifflin-St Jeor for energy expenditure, and the protein and rate-of-loss ranges, come from the certification material behind this site. The one-rep-max estimate (Epley and Brzycki) and the 7,700-calorie-per-kilogram fat conversion are a different kind of number — widely used approximations across the fitness industry, not something taught specifically in those certifications. Nothing is invented to make a tool look more precise than it is.
No fabricated experts. The only person reviewing content here is me, under my real name and my real certifications.
No invented statistics. If a claim needs a number, it either gets a range that reflects genuine uncertainty or it does not get made.
The limits get stated. A TDEE estimate is an estimate. A one-rep-max calculation depends entirely on how close to failure your input set was. Saying so is more useful than hiding it.

What this site is not

It is not medical advice, and it is not a substitute for a coach who can see you move. Calculators give you starting numbers. What you do with them over the following months is the part that matters, and that part does not automate.

If you want that side of it, I take a small number of online clients through FitActo. I do not work with anyone who has active red flags — acute pain, numbness down the leg, sciatic pain — without a doctor's assessment first.

Contact

Corrections, questions, or something that looks wrong: contact@crafnia.com. If a calculator gives an answer that does not look right, I would genuinely like to know.