Evidence-based assessment engines for bloodwork, hormones, peptides, fat loss and physique. Every formula is taken from published research or regulatory data, every result is explained, and every tool tells you how confident it is rather than presenting a single number as fact.
All tools are for educational purposes only and are not medical advice.
Most calculators online are a single equation wrapped in a form, usually with no indication of where the equation came from or how far the answer can be trusted. These are built differently, and the difference is documented rather than claimed.
Every tool is derived from peer-reviewed research, published clinical trial data or regulatory product labelling. The source is named inside each calculator, so the number it gives you can be traced back to the paper it came from. Where a published equation has since been corrected, the corrected version is the one implemented.
Each engine also reports a confidence level alongside its result. That figure moves with the quality and completeness of what you enter, which means the tool tells you when it is working from thin information instead of quietly guessing. Where individual variation is genuinely large, results are presented as a range rather than a single figure, because a decimal place implies a precision that human physiology does not have.
Blood markers are the only objective view of what is happening inside the body, and they move long before symptoms appear. This category turns a standard laboratory report into something you can actually reason about.
The bloodwork tools read each marker three ways: against the laboratory reference range, against a narrower optimal range, and against athletic or enhanced physiology where relevant. They also reason across the panel rather than marker by marker, calculating values your report did not include, such as estimated free testosterone from total testosterone and sex hormone binding globulin, insulin resistance from fasting glucose and insulin, and kidney filtration from creatinine.
The biological age tool implements a published mortality-predictive algorithm using nine routine blood markers, and breaks the result down to show how many years each individual marker is contributing.
Questions this category answers: what my blood results actually mean, whether a marker inside the reference range is genuinely optimal, what my biological age is compared with my actual age, and which markers are worth acting on first.
Hormone protocols are usually built on guesswork and adjusted by feel. These tools replace that with pharmacokinetics and measured data.
They model the blood level a given ester, dose and injection frequency produces at steady state, work backwards from a target level to the dose required, and calibrate to your own bloodwork so the projection reflects your individual response rather than a population average. Related tools cover oestrogen management, where the guidance is deliberately conservative because suppressing oestradiol too far causes more problems than mildly elevated oestradiol does, and recovery planning after a suppressive protocol.
Peptide dosing fails at the arithmetic more often than at the pharmacology. A vial arrives as powder, the concentration depends entirely on how much bacteriostatic water is added, and the resulting dose has to be read off a syringe marked in insulin units.
The reconstitution engine solves that backwards. Rather than accepting an arbitrary water volume and returning an unreadable decimal, it calculates which water volume makes your dose land on a clean, measurable syringe mark, then scores how precisely you can actually draw it and recommends a different syringe size when the graduations on your current one are too coarse.
Alongside it sits a searchable peptide database in which every compound carries an evidence grade, from approved medicines with randomised trial data down to compounds supported only by anecdote. That grading exists so that a research chemical is never mistaken for a proven medicine.
Questions this category answers: how much bacteriostatic water to add, how many units to draw, how accurate that draw actually is, and whether a given peptide has real human evidence behind it.
GLP-1 medications have become the most searched topic in this field, and most projections available online are a straight line drawn from an average trial result. Real weight loss on these drugs is not linear. It is slow during dose escalation, accelerates, then flattens into a plateau, and where that plateau sits varies enormously between individuals.
These tools model the actual curve using published trial data, adjust it for the factors that measurably change outcomes, and re-fit the entire projection to your own early response once you have one, because how much you lose in the first few months predicts your final result far better than any population average.
They also model what is being lost. A significant portion of weight lost on these medications is lean tissue rather than fat, and that proportion shifts substantially with protein intake and resistance training. Presenting only a scale number would hide the thing that matters most.
Questions this category answers: how much weight to expect and by when, how to titrate without pushing through side effects, how many units to draw from a reconstituted vial, and how much muscle is at risk.
The foundation layer. Calorie and macronutrient targets, protein requirements, body composition, and an estimate of how much muscle a given frame can carry naturally.
These are the most commonly searched calculators on the internet and also the most commonly oversimplified. The versions here model components separately rather than applying a single multiplier, account for the error in your body fat measurement rather than pretending it is exact, and personalise natural limits to your frame instead of quoting one number at everybody.
Questions this category answers: what to eat to reach a specific goal, how much protein is actually required, where body composition currently sits, and how much muscle is realistically achievable without drugs.
| If you want to | Use |
|---|---|
| You have a blood test report and want to understand it | Bloodwork Analyzer |
| You want to know how your body is ageing | Biological Age Calculator |
| You want to know what blood level a hormone protocol produces | Serum Testosterone PK Model |
| You have bloodwork and want to reach a specific level | TRT Dose Finder |
| You have a peptide vial and need to know how much water to add | Reconstitution Engine |
| You want to know whether a peptide is supported by real evidence | Peptide Database |
| You are starting or already on a GLP-1 and want to project results | GLP-1 Weight Loss Predictor |
| You need a dose calendar for semaglutide, tirzepatide or retatrutide | GLP-1 Titration Engine |
| You want calorie and macronutrient targets | Calorie and Macro Calculator |
| You want to know how much muscle you can build naturally | Max Muscular Potential |
A calculator is a model, and every model is a simplification of a real person. These are built to be as accurate as published research allows, and they are explicit about the point where that accuracy runs out.
They work from what you enter. Testing measures what is actually happening. Where a calculated estimate and a laboratory result disagree, the laboratory result is correct. The most useful role these tools play is helping you decide what to test, when to test it, and what the result means once you have it.
None of them diagnose, prescribe or replace a physician. They are educational tools, and the decisions that matter belong to you and a qualified healthcare professional who knows your history.
It depends entirely on what sits behind them. Most are a single equation with no stated source and no indication of error, which makes their output impossible to evaluate. A calculator is trustworthy when it names the research it is built on, states its assumptions, and tells you how confident it is. Every tool here does all three.
Biological age can be estimated using the Levine PhenoAge algorithm, which combines nine routine blood markers with chronological age: albumin, creatinine, glucose, C-reactive protein, lymphocyte percentage, mean cell volume, red cell distribution width, alkaline phosphatase and white blood cell count. The Biological Age Calculator on this site implements that published algorithm and also shows how many years each individual marker is adding or removing.
The nine markers used by the PhenoAge algorithm are albumin, creatinine, glucose, C-reactive protein, lymphocyte percentage, mean cell volume, red cell distribution width, alkaline phosphatase and white blood cell count. They were selected because in large population datasets they predicted mortality better than chronological age alone.
A laboratory reference range is a statistical band drawn from the population that laboratory tests, and it exists to detect disease rather than to define optimal health. A result can sit inside that range and still be well away from where you personally function best. This is why the bloodwork tools here show both the reference range and a narrower optimal range.
There is no single correct amount, because the water volume only determines concentration. The practical answer is to choose the volume that makes your intended dose land on a mark you can actually read on the syringe. The Reconstitution Engine calculates that volume for you and ranks the options.
Multiply the dose by the water volume in millilitres, divide by the total amount in the vial in micrograms, then multiply by 100 for a U-100 syringe. The Reconstitution Engine performs this calculation and additionally checks whether the resulting draw is precisely measurable on your barrel size.
A U-100 syringe holds 100 units per millilitre and is standard in the United States, United Kingdom and Europe. A U-40 syringe holds 40 units per millilitre and is common in India and in veterinary use. Confusing the two produces a dose that is wrong by a factor of two and a half.
It depends on the ester, injection frequency and your individual clearance, which varies widely between people. The TRT Dose Finder models this from published human dose-response data and can calibrate to your own measured response if you provide a current dose and the blood level it produced.
At trough, meaning immediately before the next injection, once levels have stabilised. Stabilisation takes roughly four to five half-lives of the ester in use. Testing at a random point in the cycle produces a number that cannot be meaningfully compared to anything.
Published trial averages are approximately 15 percent of body weight for semaglutide at the highest dose and up to approximately 21 percent for tirzepatide, both measured over roughly 68 to 72 weeks. Individual results vary enormously around those averages, and factors such as type 2 diabetes status substantially reduce expected loss. The GLP-1 Weight Loss Predictor adjusts for those factors and can re-fit its projection to your own response.
A meaningful proportion of the weight lost is lean tissue rather than fat, and published figures vary by drug. That proportion falls substantially with adequate protein intake and consistent resistance training. The GLP-1 tools model this explicitly rather than reporting only a scale figure.
Not for most of them. Training, nutrition and body composition tools work from measurements and training history alone. Bloodwork unlocks the more advanced tools, including the blood panel interpreter and the biological age calculator.
