Free vs Paid · 2026

What You're Actually
Paying For

One peptide calculator charges a one-time fee and runs on iOS only. The other is free, runs on iOS and Android, and has more features. Here's the honest comparison.

The Direct Comparison

Protocol (Free) vs PeptideCalc (Paid)

FeatureProtocol — FreePeptideCalc — Paid
Reconstitution calculator✓ Full✓ Full
Custom Draw reverse mode✓ Unique✗
PK half-life plotter✓ 22 compoundsBasic only
TRT ester calculator✓✗
Stack cost calculator✓ Only free one✗
Android support✓✗
Titration preview✓✓ Strong
iCloud sync✗✓
iPad support✗✓
Custom themes✗✓
PriceFreeOne-time purchase

The Honest Assessment

What PeptideCalc Gets Right

PeptideCalc's one-time purchase model is genuinely appealing — no subscription anxiety, pay once and use indefinitely. The titration preview is well-designed and shows dose escalation clearly before you commit to a schedule. iCloud sync across iPhone and iPad is useful if you use both devices. The custom theme system and cleaner visual design reflect real care for the user experience.

If you prefer one-time payments, primarily use an iPad, or want iCloud sync across devices, PeptideCalc has a defensible case. The calculation accuracy is comparable to Protocol's — both use the same underlying reconstitution math.

Where Protocol Wins on Capability

Protocol includes four calculation tools that PeptideCalc does not: Custom Draw reverse mode (specify syringe units, get BAC water amount), a PK half-life plotter for 22 compounds with multi-curve superposition, a TRT ester calculator showing free testosterone content per ester, and a stack cost calculator. Each of these solves a real calculation problem that PeptideCalc leaves to mental math or a spreadsheet.

Protocol also runs on Android — PeptideCalc does not. For the roughly half of smartphone users on Android, Protocol is the only full-featured peptide calculator available natively.

The one-liner

If you need iCloud sync and iPad support and are happy on iOS, PeptideCalc is worth evaluating. If you need Custom Draw, Android, or more than basic reconstitution, Protocol is the clear choice.

FAQ

Common Questions

Is there a completely free peptide calculator with no limitations?
Yes. Protocol's calculator suite is fully free — no account required, no feature caps, no expiring trial. The full five-tool suite (reconstitution, Custom Draw, PK plotter, TRT ester, stack cost) is available on iOS and Android. The reconstitution calculator and Custom Draw mode are also free on the web at reconstitution.health with no download.
Does a paid peptide calculator give more accurate results?
No. All major peptide calculators use the same concentration and draw unit formulas. Accuracy differences between apps are negligible — the math is simple arithmetic. The differences between paid and free calculators are in features (Custom Draw, PK modeling, additional tools), platform support (Android), and interface design — not calculation accuracy.
What does PeptideCalc cost?
PeptideCalc uses a one-time purchase pricing model rather than a subscription. The specific price may vary — check the App Store listing for the current price. It's iOS only and not available on Android.

Five Tools. Zero Cost.

The complete free peptide calculator suite on iOS and Android.

App Store Google Play

No account · On-device only · iOS + Android