Free Health Calculators
Every calculator shows its formula, a worked example and a printed reference chart — so the answer is there whether or not you use the tool.
Dosing & injection
- Bacteriostatic Water CalculatorHow much bacteriostatic water to add, the concentration it produces, units per dose and doses per vial. With the full mixing chart.
- Syringe SelectorWhich barrel holds your volume, and what its numbers mean. “Draw 0.5” is 0.5 mL on a luer-lock and 0.005 mL on an insulin barrel.
Hair loss
- Norwood ScaleStages I–VII of male pattern hair loss, drawn from above and from the front, plus the Type A variants.
- Topical Finasteride Concentration CalculatorPercent to mg/mL and back, mass or volume for a target strength, milligrams per application and days per bottle — with the full dilution chart.
- Minoxidil bottle duration calculatorDays, weeks and bottles from the labelled 1 mL twice a day — plus the one minoxidil product whose supply cannot be worked out at all.
Hormones
- Free Testosterone CalculatorFree and bioavailable testosterone from total T, SHBG and albumin. Vermeulen method, with the full conversion chart.
- TRT cost per month calculatorThe true monthly cost of TRT across self-pay, telehealth and clinic routes, with the vial price you were actually quoted.
- Testosterone dose calculatorWeekly mg split across your injection interval, then converted to mL and U-100 units at your vial’s strength.
- Testosterone Unit ConverterTotal T between ng/dL, nmol/L and ng/mL; free T between pg/mL, ng/dL, pmol/L and percent — with the factor derived from the molar mass.
- Bioavailable Testosterone CalculatorBioavailable testosterone — free plus albumin-bound — from total T, SHBG and albumin, with the whole partition of the sample shown.
- Estradiol Unit ConverterEstradiol between pg/mL, pmol/L, nmol/L and ng/L — plus what immunoassay and mass spectrometry disagree about at the concentrations men are measured at.
- hCG Reconstitution CalculatorTurns a 5,000 or 10,000 IU vial and a diluent volume into IU per mark, so 500 IU becomes 50 marks and not 500. Built on the two approved labels.
Labs & biomarkers
- LDL Cholesterol CalculatorLDL-C by all three equations — Friedewald, Martin-Hopkins and Sampson — side by side, in mg/dL or mmol/L.
- HOMA-IR CalculatorHOMA-IR and HOMA-B beta cell function from a fasting glucose and insulin, in either unit system, with the full matrix chart.
- A1c to Average Glucose ConverterHbA1c to estimated average glucose in mg/dL or mmol/L, plus NGSP % to IFCC mmol/mol — with the real spread around each estimate.
- Testosterone Reference Range by AgeYour total testosterone as a percentile among men your own age, from the published Travison centiles — plus what that does and does not mean.
- eGFR CalculatorEstimated GFR by the 2021 CKD-EPI equations, which carry no race coefficient, in mg/dL or µmol/L, with cystatin C confirmation.
- Cholesterol Unit ConverterA whole lipid panel between mg/dL and mmol/L, with the triglyceride factor kept separate from the cholesterol one — the commonest error on a lipid report.
Peptides
- Peptide Reconstitution CalculatorTurns a milligram vial and a millilitre of diluent into micrograms per unit mark, so a 250 mcg dose becomes a number you can draw. No dosing protocol.
- Peptide mcg to mg ConverterThe pure unit conversion: mcg ⇄ mg needs nothing but a number, and the syringe leg needs only a concentration. Reads forwards from a dose and backwards from a mark.
- Peptide Blend CalculatorTwo peptides, one vial, one syringe. What each mark carries of each, why the ratio cannot be changed after mixing, and what that costs. No dosing protocol.
Sexual health
- ED medication onset and duration plannerOnset and duration for all four ED tablets on one timeline, read off the FDA labels — plus when to take yours.
- ED Medication Cost Per DoseCost per dose, not per tablet, for all four PDE5 inhibitors — at the acquisition price CMS actually publishes.
- PDE5 Inhibitor Dose EquivalenceNo conversion table exists between the four ED tablets. What each label states instead, and why the ratio everyone repeats is arithmetic on round numbers.
Weight loss & GLP-1
- Semaglutide units converterSemaglutide mg, mcg and U-100 syringe units at your vial’s concentration. Full conversion chart and reconstitution table.
- Retatrutide Dosage CalculatorReconstitution and mg-to-units arithmetic for retatrutide, plus the doses actually used in the published phase 2 trials. Investigational compound.
- Tirzepatide units converterTirzepatide mg, mcg and U-100 syringe units at your vial’s concentration. Full conversion chart plus the Mounjaro and Zepbound label ladders.
- GLP-1 Titration PlannerYour start date plus the FDA-labelled ladder, as dates: which dose in which week, and the earliest each step is allowed.
- Weight Loss Percentage CalculatorPercentage of body weight lost, in kg or lb — placed next to what the GLP-1 trials actually reported, caveats attached.
- Liraglutide units converterLiraglutide mg, mcg, mL and units — pen supply arithmetic plus the XULTOPHY dose-counter conversion the label actually authorises.
- GLP-1 cost comparisonWhat a pharmacy paid for every approved GLP-1, per injection and per month, from the CMS NADAC file — with your own monthly price set against it.
Educational reference, not medical advice.