Peptide Aliquot Calculator
Calculate how many equal aliquots a stock solution yields, and how much volume is left over.
Calculate Aliquots from a Stock Solution
Enter your total stock solution volume, then specify aliquots either by a fixed volume per aliquot or by a target quantity per aliquot (which requires a known stock concentration).
Results update instantly as you type. This tool performs a mathematical calculation only — always independently verify results before using them in a laboratory procedure.
How This Calculator Works
Once a peptide stock solution is prepared, it is often divided into smaller, single-use aliquots for storage or downstream sample preparation. This calculator determines how many complete aliquots a given total volume can be divided into, and how much volume is left over. You can specify the aliquot size directly, or specify a target quantity per aliquot along with a known stock concentration and let the calculator determine the corresponding volume first.
Formula and Unit Definitions
Number of complete aliquots = total volume ÷ aliquot volume, rounded down to a whole number
Remaining volume = total volume − (number of aliquots × aliquot volume)
Aliquot volume from a target quantity = target quantity ÷ stock concentration
Volumes may be entered in mL or µL, and mass quantities in mg or µg. Stock concentration may be entered in mg/mL or µg/mL. All values are standardized internally before the calculation runs.
Worked Laboratory Example
Suppose you have 2 mL of stock solution and want 100 µL aliquots.
Number of complete aliquots = 2 mL (2,000 µL) ÷ 100 µL = 20 aliquots
Remaining volume = 2,000 µL − (20 × 100 µL) = 0 µL
If instead you wanted 300 µL aliquots, the same 2,000 µL would yield 6 complete aliquots (1,800 µL used) with 200 µL remaining.
Accuracy and Limitations
- The whole-aliquot count is rounded down; a solution never yields a fractional aliquot in practice.
- This calculator assumes no volume is lost to pipetting, transfer, or container dead volume.
- Results are only as accurate as the total volume, aliquot size, and (where used) concentration values supplied.
See the full calculation methodology for rounding rules and validation logic.
Frequently Asked Questions
What is a laboratory aliquot?
An aliquot is a measured portion taken from a larger volume of solution, typically stored or used separately, such as in individual sample tubes.
Why is there leftover volume after splitting into aliquots?
The total volume does not always divide evenly into whole aliquots. The calculator rounds down to a whole number of complete aliquots and reports the remaining volume separately.
What is the difference between specifying aliquot volume and target quantity?
Specifying aliquot volume splits the stock solution by volume directly. Specifying a target quantity per aliquot instead calculates the required volume from a known stock concentration, then splits the solution using that calculated volume.
Can this calculator be used for human or animal dosing?
No. This calculator is not designed for, and must not be used for, human or animal dosing. It is a mathematical tool intended for laboratory sample planning only.