Free Tools

Injectable Calculators

All InjectBuddy calculators are free, run entirely in your browser, and require no login. No health data is ever sent to any server.

21calculators

6categories

0data stored

Testosterone (TRT) & Hormone Therapy

Testosterone (TRT)

Testosterone (TRT) Dose Calculator

Enter your weekly testosterone dose and vial concentration — get your exact draw volume in mL and insulin units. Supports any injection frequency.

→ Read the Testosterone (TRT) dosing guide →

Testosterone (TRT)

Testosterone (TRT) & EOD Calculator

Every-other-day protocol calculator. Calculates per-injection dose and volume for EOD or any split frequency from your prescribed weekly total.

→ Read the injection frequency guide →

Testosterone (TRT)

Testosterone (TRT) Microdose Calculator

Split a weekly testosterone dose into small daily or EOD microdoses. Get the per-injection dose and exact insulin units for steady, low-fluctuation levels.

→ Read the Testosterone (TRT) microdose guide →

Testosterone (TRT)

HCG Dosage Calculator

Calculate your HCG draw volume in mL and insulin units from your vial strength, BAC water volume, and prescribed IU dose. Supports 2,000, 5,000 and 10,000 IU vials.

→ Read the HCG reconstitution guide →

Testosterone (TRT)

Ester Bioavailability & Half-Life

Model steady-state peak, trough and peak:trough ratio for any testosterone, nandrolone, tren, mast or EQ ester. See how injection frequency and IM vs SubQ change the curve, with a 4-week graph.

→ Read the testosterone esters guide →

Testosterone (TRT)

Pharmacokinetic blood-level graph for injectable steroids and Testosterone (TRT) compounds. Plot serum levels over a full cycle — see peak, trough, steady-state day, and washout.

→ Read the Testosterone (TRT) protocols guide →

Other

Nootropic Dosing Calculator

Work out a per-dose and daily nootropic dose for racetams, noopept, modafinil, L-theanine and more. Scales racetams by bodyweight and tolerance, with redose timing and stimulant cycling guidance.

Estradiol (E2) Estimator

Get a rough serum-estradiol range and water-retention / gyno risk read from your weekly testosterone dose, AI, body fat and age. A heuristic only — bloodwork always supersedes.

→ Read the Testosterone (TRT) bloodwork guide →

Women’s Hormone Health

Female HRT Planner

Build a menopause or female hormone regimen: estradiol route and dose with approximate serum-E2 targets, progesterone schedule, female-dose testosterone and application rotation. Educational, prescriber-supervised.

→ Read the women’s testosterone guide →

GLP-1 Weight Loss Medications

Semaglutide Dosage Calculator

Calculate your semaglutide draw volume in mL and insulin units from your prescribed dose (mg) and vial concentration. Works with compounded vials.

→ Read the semaglutide dosing guide →

Tirzepatide Dosage Calculator

Calculate your tirzepatide draw volume from your prescribed dose and vial concentration. Supports all standard dose escalation levels.

→ Read the tirzepatide dosing guide →

Retatrutide Dosage Calculator

Calculate your retatrutide draw volume in mL and insulin units from your prescribed dose (mg) and vial concentration. Built for the triple-agonist GLP-1.

→ Read the retatrutide dosing guide →

GLP-1 Titration Planner

Build a week-by-week dose escalation schedule for semaglutide, tirzepatide or retatrutide. Choose your start and target dose and pace to see units per week, vial count and totals.

→ Read the GLP-1 titration guide →

Peptide Calculators

Peptide Reconstitution Calculator

Calculate how much BAC water to add to your peptide vial to reach your target concentration. Enter vial size (mg) and desired mg/mL to get the exact mL of water.

→ Read the peptide reconstitution guide →

Reverse Dose Solver

Know any two values and solve the rest. Enter vial total, concentration, dose, or syringe units and the solver fills in concentration, draw volume, U-100 units and doses per vial.

→ Read the reverse dose guide →

Peptide Dosage Calculator

Calculate your peptide injection volume in mL and insulin units from your prescribed dose (mcg or mg) and reconstituted concentration.

→ Read the injection volume guide →

BPC-157 Dosage Calculator

Calculate BPC-157 draw volume in mL and units from your dose (mcg), vial size, and BAC water volume. Includes vial duration estimate.

→ Read the BPC-157 peptide guide →

Blend Calculator

Work out the per-injection mg of every compound in a multi-ester oil blend like Sustanon 250 or TMT. Enter each compound's mg/mL and your injection volume for a full breakdown plus weekly totals.

→ Read the testosterone esters guide →

BPC-157 + TB-500 Blend Calculator

Calculate draw volumes for combined BPC-157 and TB-500 blends. Accounts for individual peptide ratios and combined vial concentration.

→ Read the BPC-157 + TB-500 guide →

Body Composition

Calculate your Body Mass Index from height and weight. Displays WHO category (underweight, normal, overweight, obese) with metric and imperial support.

Free Testosterone Index Calculator

Calculate your Free Androgen Index (FAI) from total testosterone and SHBG lab values. Useful for interpreting bloodwork during Testosterone (TRT).

→ Read the free androgen index guide →

Free Testosterone Calculator

Estimate free and bioavailable testosterone in pg/mL from total T, SHBG and albumin using the Vermeulen equation — more accurate than the FAI proxy.

→ Read the free testosterone guide →

How Testosterone (TRT) & peptide calculators work

Every InjectBuddy calculator turns a dose (how much medication you take, in mg, mcg or IU) into a draw volume (how far to fill the syringe, in mL or insulin units). The link between them is your vial's concentration — for example 250 mg/mL or a reconstituted 5 mg/mL peptide.

For powdered peptides and HCG you first reconstitute the vial by adding bacteriostatic water. The amount of water you add sets the mg/mL, which in turn sets how many insulin syringe units a given dose draws up — on a U-100 syringe, 100 units equals 1 mL.

Pick the calculator that matches your compound, enter your numbers, and read off the exact mL and units. Everything runs in your browser — no dose, weight or vial detail ever leaves your device.

Frequently asked questions

Are InjectBuddy's calculators free?

Yes. Every calculator on InjectBuddy is completely free, with no login, no trial and no paywall. The core dosing maths will always stay free.

Is my health data stored anywhere?

No. Every calculation runs entirely in your browser. Your doses, weights and vial details are never sent to a server and never saved.

What's the difference between dose and draw volume?

Your dose is how much medication you take (in mg, mcg or IU). Draw volume is how far you fill the syringe (in mL or insulin units) to deliver that dose, based on your vial's concentration.

Which calculator do I need?

For testosterone use the Testosterone (TRT) Dose calculator; for semaglutide or tirzepatide use the matching GLP-1 calculator; for peptides like BPC-157 start with the Peptide Reconstitution calculator, then the dosage calculator.

Can I rely on these calculators for medical decisions?

No. InjectBuddy performs mathematical calculations only and is not medical advice. Always confirm your dose with your prescribing doctor, nurse or pharmacist before injecting.

Do the calculators work on mobile?

Yes. Every calculator is built mobile-first and works in any modern phone browser, with no app install required.

What are insulin syringe units?

A U-100 insulin syringe is marked in units, where 100 units equals 1 mL. Many calculators convert your draw volume into units so you can measure small doses accurately. Learn more about syringe units.

Can I embed these calculators on my own site?

Yes. Most calculators offer an embed mode so clinics, coaches and communities can add them to their own pages. See the embed page for details.

Related guides

Pair these calculators with our dosing and protocol guides for step-by-step walkthroughs, titration schedules, and storage guidance: