OptiPin
Free calculators
19 free, no-login tools for TRT, steroids, peptides and GLP-1, plus per-compound reconstitution guides. Every calculation can also be tracked and forecast over time in OptiPin.
Peptide Reconstitution Calculator
Enter vial size, BAC water, and target dose for the exact syringe units. 200+ medications, typical-dose hints, and one-tap blend expansion (GLOW, KLOW, Wolverine, and more).
Peptide Blend Calculator
Multi-compound stacks (Wolverine, GLOW, KLOW, GH Stack) – tap a preset or build your own and get the exact per-peptide syringe units.
Free Testosterone Calculator
Vermeulen equation – total T, SHBG, and albumin → free and bioavailable testosterone and percent free.
TRT Dose Calculator
Weekly dose + concentration + frequency → mL and insulin units per injection, and how long a vial lasts.
Half-Life Visualizer
Plot single-dose and steady-state blood-level curves for 60+ compounds, with time to peak and steady state.
Reverse Dose Calculator
Already drew it? Units back to milligrams, with a comparison against the dose you meant to take and a full units-to-mg chart.
Vial Transition Calculator
New vial at a different concentration – the units to draw for the same dose, how far off your old count would be, and splitting one dose across two vials.
Split Dose Calculator
Weekly to twice weekly, every few days, or fixed days of the week, holding the weekly total. Monday and Thursday are 3 days apart one way and 4 the other, so the doses follow the gaps. Shows the per-injection dose, the units, and how much flatter your levels actually get for your compound's half-life.
HCG Dosage Calculator
Vial IU + bacteriostatic water + target dose → insulin units to draw, concentration, and doses per vial. Includes a full reconstitution and mixing chart.
Vial Longevity & Cost
Doses and weeks per vial plus cost per dose – works for peptides (total mg) or oil vials (size × concentration).
Insulin Syringe Units Chart
Units → mL → mcg. Why 1 unit is always 0.01 mL, the mcg-per-unit tables for every common reconstitution, and the U-40 warning.
mg to Units Calculator
How many units is your mg or mcg dose? Enter the vial and the water, or the printed mg/mL, then read the units. Includes the 1 mg, 2 mg and 5 mg cases.
Units to mg Calculator
How much drug is in the units you drew? Units are a volume, so the concentration decides whether 10 units is 250 mcg or 1000 mcg.
Units to mL Calculator
Divide by 100 on a U-100 barrel. The one syringe conversion that never depends on what is in the vial, with the full table and the U-40 warning.
IU to mL Calculator
For vials labeled in international units. Vial IU plus diluent gives milliliters and syringe units, with the 3.0 IU/mg somatropin factor.
Testosterone Levels by Number
ng/dL ↔ nmol/L (and E2, DHT, free T), then what the number means: every common result banded against the harmonised reference range and the three guideline thresholds.
Peptide Storage & Shelf Life
How long peptides last as powder and reconstituted, why the 28-day figure is a preservative limit rather than a stability limit, and what actually degrades a peptide.
Steroid Cycle Calculator
Total weekly milligrams across a stack, the hormone actually delivered once ester weight is removed, plus time to plateau.
PCT Calculator
When each compound in a cycle clears, which ester governs the wait, plus the earliest sensible start date.
Steroid Ester Calculator
250 mg of enanthate is not 250 mg of testosterone. Active hormone per dose, plus equivalents in every other ester.
GLP-1 Titration Schedule
The standard manufacturer titration for Wegovy, Ozempic, and Mounjaro/Zepbound, mapped to dates from your start date.
GLP-1 Pen Click Charts
What a "click table" means and the click-to-mg mechanics for Ozempic and Mounjaro/Zepbound pens – plus why Wegovy has no clicks. Reference only.
Low Testosterone Quiz
10-question ADAM screening questionnaire – see whether your symptoms match the low-testosterone pattern. Educational, not a diagnosis.
Reconstitution guides by compound
The calculator handles any compound. These go deeper on one each: the water volume that actually suits its dose range, a full dose-to-units chart, and the specific way people get that compound wrong.
Semaglutide reconstitution
The whole 0.25–2.4 mg titration ladder in units, for 5 mg and 10 mg vials.
Tirzepatide reconstitution
10 to 60 mg vials, and the concentration a 15 mg dose needs to fit one syringe.
Retatrutide reconstitution
Dose-to-units for 5, 10, 12 and 30 mg vials, plus storage and beyond-use dating.
BPC-157 reconstitution
Microgram dosing, the mcg-to-mg conversion, and why it needs more water not less.
Tesamorelin reconstitution
Why the obvious 2 mg in 2 mL mix overflows a U-100 syringe.
HGH reconstitution
IU versus insulin units, the mg-to-IU conversion, and charts for every vial size.
NAD+ reconstitution
500 mg and 1000 mg vials, and why concentrating it matters more for comfort than for accuracy.
Track and forecast it all in OptiPin
Log doses, rotate sites, manage inventory, and forecast testosterone, estrogen & GLP-1 levels between blood draws – all on-device, no account required.
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