Peptide Concentration Calculator — mg/mL, mcg/mL, percent & dilution C1V1=C2V2.
A free peptide concentration calculator that solves the c = m ÷ V relationship in either direction. Type a peptide mass and diluent volume to read the concentration in mg/mL, mcg/mL or percent — or switch modes to solve for mass, for volume, or to apply the dilution equation C1V1=C2V2. Formula shown on every result.
Open the concentration calculator Use the reconstitution calculator
Free peptide concentration calculator
Solve for the concentration of a peptide solution, the mass of peptide to weigh out, the volume of diluent to add, or the dilution C1V1=C2V2 — all in one page. Pick a mode, enter the two values you know, and read the answer in mg/mL, mcg/mL or percent.
Result — peptide concentration
What Is the Peptide Concentration Calculator?
The peptide concentration calculator on PeptideCalculatorTools.com is a small math tool that solves the c = m ÷ V relationship in every direction. You give it two of the three values — peptide mass, diluent volume, or the resulting concentration — and it returns the missing one. It also runs the dilution equation C1V1 = C2V2 for situations where a stock solution has to be diluted to a working concentration.
The result panel reports the same answer in mg/mL, mcg/mL, and percent (w/v) at the same time, and converts the concentration to micrograms per insulin-syringe mark when you select U-100, U-50 or U-30. This is the same number our peptide reconstitution calculator, BAC water calculator and peptide dilution calculator use internally — presented here as a standalone, bidirectional tool.
How to Use the Peptide Concentration Calculator
1. Pick the mode
Choose Solve for concentration when you know both the mass and the volume; choose Solve for mass when you have a target concentration and a target volume; choose Solve for volume when you have a peptide mass and a target concentration; choose Dilution C1V1=C2V2 when you need to dilute a stock solution to a new concentration or volume.
2. Enter the two (or three) knowns
The mass field accepts mg, µg or g; the volume field accepts mL, µL or L; the concentration field accepts mg/mL, µg/mL or mg/L. The calculator normalises to mg and mL internally. For dilution, fill any three of the four C1/V1/C2/V2 fields and leave the unknown blank or at zero — the result panel highlights the value it solved for.
3. Read the result
The result card shows your chosen primary unit, plus the same answer in mg/mL, mcg/mL and percent (w/v). If a U-100, U-50 or U-30 syringe is selected, the result also reports the microgram per insulin mark. Use the action row to reset, copy a plain-text result, print a worksheet or copy a shareable URL with your inputs embedded.
How the Concentration Math Works
The peptide concentration formula
c = m ÷ V
c is the concentration in mg/mL, m is the peptide mass in mg, V is the diluent volume in mL. The same formula is rearranged two ways depending on which variable is missing: m = c × V when you know the target concentration and volume, and V = m ÷ c when you know the mass and the target concentration. All three forms are implemented in this calculator.
mg/mL ↔ mcg/mL ↔ percent
1 mg/mL = 1 000 µg/mL. To convert mg/mL to percent (w/v), multiply by 0.1 — 5 mg/mL = 0.5% (w/v), because 5 mg per 1 mL equals 5 g per 1 L. The calculator shows all three at once so you do not have to convert by hand.
Reading micrograms per insulin mark
Each U-100 insulin mark holds 0.01 mL; each U-50 mark 0.02 mL; each U-30 mark ≈ 0.033 mL. With a concentration of c mg/mL, each U-100 mark draws c × 0.01 × 1 000 = c × 10 µg. At 5 mg/mL you get 50 µg/U on U-100, 100 µg/U on U-50, and ≈ 167 µg/U on U-30.
Dilution C1V1 = C2V2
The dilution equation balances the mass of solute on both sides of the dilution. Enter any three of the four fields and the calculator solves the missing one. The "diluent to add" line tells you how much extra diluent to draw up to reach the target volume: diluent = V2 − V1.
Peptide Concentration Quick Reference
How the same concentration reads across the units you will encounter in a lab or on a calculator.
| mg/mL | µg/mL | Percent (w/v) | µg per U-100 mark | µg per U-50 mark |
|---|---|---|---|---|
| 0.1 | 100 | 0.01% | 1 µg/U | 2 µg/U |
| 0.5 | 500 | 0.05% | 5 µg/U | 10 µg/U |
| 1.0 | 1 000 | 0.10% | 10 µg/U | 20 µg/U |
| 2.0 | 2 000 | 0.20% | 20 µg/U | 40 µg/U |
| 2.5 | 2 500 | 0.25% | 25 µg/U | 50 µg/U |
| 5.0 | 5 000 | 0.50% | 50 µg/U | 100 µg/U |
| 10.0 | 10 000 | 1.00% | 100 µg/U | 200 µg/U |
The same mass per mL of diluent reads differently on U-100 and U-50 syringes because a U-50 mark holds twice the volume. Always pick the syringe you are actually drawing with.
Worked Examples
Example 1 — 10 mg in 2 mL → concentration (Mathematical Example)
c = 10 ÷ 2 = 5.000 mg/mL = 5 000 µg/mL = 0.500% (w/v). On a U-100 syringe each mark draws 50 µg/U.
Example 2 — Solve for mass (2 mg/mL × 5 mL)
m = 2 × 5 = 10.000 mg of peptide. Dissolve in 5 mL of diluent to reach a 2 mg/mL working concentration.
Example 3 — Solve for volume (10 mg ÷ 2 mg/mL)
V = 10 ÷ 2 = 5.000 mL of diluent. With 10 mg of peptide and a target of 2 mg/mL, the calculator tells you to add 5 mL of bacteriostatic water.
Example 4 — Dilution C1V1 = C2V2 (5 mg/mL × 2 mL → 1 mg/mL × V2)
C1V1 = 5 × 2 = 10. C2V2 = 1 × V2 = 10 → V2 = 10.000 mL. Diluent to add: 10 − 2 = 8.000 mL.
Example 5 — Percent conversion sanity check
5 mg per 1 mL = 5 g per 1 000 mL = 0.5% (w/v). The calculator returns 0.500% for the same inputs as Example 1, so the percent reading matches a standard percent (w/v) label on a stock solution.
Common Concentration Mistakes
Percent (w/v) = grams of solute per 100 mL of solution, used here. Percent (w/w) = grams of solute per 100 g of solution. For dilute aqueous peptide work the two numbers are close but not identical; this calculator reports w/v.
1 mg/mL = 1 000 µg/mL. A stock solution labelled 5 mg/mL is the same as 5 000 µg/mL. Always read the unit selector before reading the number — switching units by accident will give an answer that is 1 000 × off.
A 5 mg/mL solution draws 50 µg on a U-100 mark but 100 µg on a U-50 mark. The calculator's Per insulin mark stat changes when the syringe selector changes — use it to confirm the physical syringe you are drawing with.
The dilution mode solves whichever of C1/V1/C2/V2 is at zero. If you leave the wrong field at zero (for example, because the previous answer was zero), the calculator will solve the wrong variable. Clear all four fields and re-enter only the three you know.
Peptide Concentration Calculator FAQ
What does the peptide concentration calculator do?
It converts a peptide mass and a diluent volume into a concentration (mg/mL, mcg/mL, percent, or micrograms per insulin-syringe unit), and it works in reverse — solving for mass or volume when two of the three are known. It also handles dilution C1V1=C2V2.
How do I calculate peptide concentration in mg/mL?
Concentration (mg/mL) = peptide mass (mg) ÷ diluent volume (mL). Example: 10 mg of peptide dissolved in 2 mL of bacteriostatic water gives 10 ÷ 2 = 5.000 mg/mL.
What is the peptide concentration formula?
c = m ÷ V. Rearranged: m = c × V, and V = m ÷ c. All three forms are implemented in this calculator — pick the mode that matches the two values you already know.
How do I convert mg/mL to mcg/mL?
1 mg/mL = 1 000 mcg/mL. Multiply by 1 000 to convert mg/mL to mcg/mL; divide by 1 000 to convert mcg/mL back to mg/mL. The calculator does this automatically and shows both values side by side.
How do I dilute a peptide solution using C1V1=C2V2?
C1 is the starting concentration, V1 is the starting volume, C2 is the target concentration, and V2 is the target volume. C1V1 = C2V2. Enter any three to get the fourth. Example: 5 mg/mL × 2 mL = 1 mg/mL × 10 mL — start with 2 mL of a 5 mg/mL solution and add 8 mL of diluent to reach 10 mL at 1 mg/mL.
How many micrograms are in one insulin-syringe unit?
That depends on the concentration. With a resulting concentration of c mg/mL, each U-100 mark (0.01 mL) draws c × 10 micrograms. At 5 mg/mL you get 50 µg/U; at 2 mg/mL you get 20 µg/U. The calculator shows the mcg/U number alongside the mg/mL reading.
Can I solve for volume instead of concentration?
Yes. Switch the mode to Solve for volume. The calculator then divides the peptide mass by your target concentration. Example: 10 mg ÷ 2 mg/mL = 5.000 mL of diluent.
Can I solve for mass instead of concentration?
Yes. Switch the mode to Solve for mass. The calculator then multiplies the target concentration by the diluent volume. Example: 2 mg/mL × 5 mL = 10.000 mg of peptide.
Is this calculator medical advice?
No. The peptide concentration calculator is a math tool. It does not give medical advice, recommend a concentration or dose for any person, or model pharmacokinetics. Presets are user-input examples, not recommended concentrations.
Can I share my inputs with someone else?
Yes. Click Copy share link. The button copies a URL with your mode and the values you entered embedded; opening that URL restores the same inputs.
Related Peptide Calculators
The peptide concentration calculator on this page performs mathematical conversions only. It does not give medical advice, recommend a concentration or dose for any person, or model pharmacokinetics. The presets are user-input examples, not recommended concentrations. Read the full medical disclaimer and the site disclaimer.