Browser extension
Unit Converter
mg, mcg, mL, µL, mg/mL, dilutions and molarity, in one fast popup that works offline.
The Unit Converter is a fast, general lab converter: type a value, pick two units and copy the answer. Mass, volume, concentration, moles and molarity are covered, plus a concentration tool and a C1·V1 = C2·V2 dilution solver.
When a conversion needs more information, it says so instead of guessing: moles need an exact molecular weight, IU needs the substance’s own factor, and mass never turns into volume without a concentration.
Coming soon to Chrome, Edge, Firefox, Opera and Safari
Account: No.
What it does
Everyday units
g, mg, mcg (µg) and ng; L, mL and µL; mg/mL, mcg/mL, mcg/µL, ng/mL and % w/v.
Molar conversions
Moles and molarity (M, mM, µM, nM) with a molecular weight you enter, or a Peptide Library profile’s exact weight.
Dilutions
Fill in three of C1, V1, C2 and V2 and the fourth is solved; a final concentration above the stock is refused.
History and pins
Finished conversions are kept on your device; pin the pairs you use most.
Address bar
Type “pl”, a space and “250 mcg to mg” in Chrome, Edge, Firefox or Opera and the answer appears as you type.
How it works
Every conversion runs locally with exact decimal arithmetic. The only network request is an optional lookup of a peptide’s molecular weight or IU factor.
This is a converter, not a dosing tool: it has no vial, diluent or syringe workflow (that’s the Peptide Calculator).
Privacy
- • History and pins stay on your device.
- • No access to the pages you visit.
Full details: privacy policy · support
Browser support
| Browser | Needs | Get it |
|---|---|---|
| Google Chrome | Chrome 116 or later | Coming soon |
| Microsoft Edge | Edge 116 or later | Coming soon |
| Mozilla Firefox | Firefox 140 or later | Coming soon |
| Opera | Opera 102 or later | Coming soon |
| Safari | Safari 17 or later | Coming soon |
On peptidelibrary.app
- Insulin syringe units converter · Units, mL and U-100 markings explained.
- Peptide calculator · Reconstitution and draw volumes.
- Peptide Library · Molecular weights and IU factors per profile.
Frequently asked questions
How do I convert mcg to mg?
Divide by 1,000: 250 mcg is 0.25 mg. In the extension, type 250, choose mcg → mg, and copy the result.
Can it convert IU to mg?
Only with the IU-per-mg factor of that exact substance. IU measures biological activity and differs between substances, so there is no universal conversion.
How are moles and molarity calculated?
From the molecular weight in g/mol: moles = mass ÷ molecular weight, and molarity = mass concentration (g/L) ÷ molecular weight. Approximate or ranged weights are refused.
Does it work offline?
Yes. Every conversion runs in your browser; only looking up a peptide’s molecular weight needs a connection.
Why won’t it convert mg to mL?
Mass and volume measure different things. You need a concentration: use the Concentration tab, or the Peptide Calculator for reconstitution.
More Peptide Library extensions
Research and educational use only. Not medical advice. Peptide Library does not sell peptides.