Peptide Calculator
Peptide reconstitution calculator.
Work out concentration, how much liquid to add, aliquot volumes and molarity in seconds. No sign-up, and it works on your phone at the bench.
Reconstitute a vial
Find the concentration after adding liquid to a freeze-dried peptide vial.
How much liquid to add
Choose the concentration you want and get the exact volume of liquid to add.
Split into aliquots
Uses the vial and liquid from the Reconstitute tab. Enter the amount you need per sample.
Stock: · change it on the Reconstitute tab.
Molarity
Convert a peptide solution to mM and µM using its molecular weight.
Four formulas, shown plainly.
Every result shows its working, so you can check it by hand or record it in your lab notebook.
Concentration
mg ÷ mL = mg/mL5 mg in 2 mL gives 2.5 mg/mL, or 2,500 µg/mL.
Volume to add
mg ÷ target mg/mL = mLFor 2 mg/mL from a 10 mg vial, add 5 mL.
Volume per sample
µg ÷ µg/mL × 1000 = µL250 µg at 2,500 µg/mL is 100 µL per aliquot.
mg/mL to mM
(mg/mL ÷ g/mol) × 1000 = mMUse the molecular weight on your certificate of analysis.
Calculator FAQs.
Quick answers about reconstitution maths. For the full method, including which liquid to use and how to store the solution, read our step-by-step guide.
Divide the amount of peptide in the vial (mg) by the volume of liquid you add (mL). For example, 5 mg in 2 mL gives 2.5 mg/mL, which is 2,500 µg/mL. The calculator above does this instantly and converts between units.
The amount of liquid does not change how much peptide is in the vial, only how concentrated the solution is. More liquid means a lower concentration and larger volumes per sample, which can be easier to measure accurately. Use the "Liquid needed" tab to hit a round concentration such as 1 mg/mL.
The weight on a label is usually the total powder, which includes counter-ions (such as acetate or TFA) and some water. The net peptide content on your certificate of analysis (often 70–90%) is the real peptide share. For precise quantitative work, switch on the net content option and enter that percentage.
Molarity depends on the peptide's molecular weight. Divide the concentration in mg/mL by the molecular weight in g/mol to get mol/L, then multiply by 1,000 for mM. The Molarity tab handles this; use the molecular weight from your COA.
Decide the amount you need per sample, use the Aliquots tab to get the volume in µL, then dispense that volume into separate labelled tubes and freeze them. Thawing each aliquot only once protects the peptide from freeze–thaw damage.
No. It is a laboratory calculator for concentrations, dilutions, aliquots and molarity. Lian Peptides products are sold for research use only and are not for human or veterinary use, so we do not provide dosing or administration guidance.
Get the right liquid for your vials.
Sterile diluents to go with your research peptides, shipped with your order.
This calculator performs laboratory concentration, dilution and molarity maths only. Lian Peptides products are for research use only, are not medicines and are not for human or veterinary use. Always confirm critical values by hand.
