Plan a step-by-step serial dilution
A serial dilution calculator turns one starting concentration into a sequence of progressively lower concentrations. Choose a fixed dilution factor or provide a starting and target concentration so the calculator can determine the equal factor needed at each step. It then reports every tube or well, the concentration after that dilution, the cumulative dilution from the original stock, and the transfer and diluent volumes associated with the chosen final volume.
Serial dilution is useful when one direct transfer would be too small to measure reliably or when an experiment needs a concentration series. A tenfold series, for example, is easier to prepare and review as repeated 1:10 steps than as a single 1:1,000 transfer. The arithmetic does not select pipettes, tolerances, mixing technique, containers, sterility, or a scientifically suitable concentration range; those choices still come from the protocol and equipment.
Understand concentration, step factor, and overall dilution
For equal steps, concentration after step i is Ci = C0 ÷ D^i, where C0 is the original concentration, D is the per-step dilution factor, and i starts at one for the first diluted tube. After n steps, the overall dilution factor is Doverall = D^n. A factor of 10 means one part transferred material in ten parts final mixture, not one part plus ten parts diluent.
If the starting concentration, target concentration, and number of steps are known, the equal per-step factor is the nth root of C0 ÷ Ctarget. The target must be below the starting concentration for a dilution series. Very large factors raised through many steps can exceed useful numeric or laboratory ranges, so review the displayed cumulative factor and concentrations instead of assuming that every mathematically possible sequence is practical.
Work through a 1:10 dilution series example
Start with 100 mg/mL and choose three 1:10 steps. The first diluted tube is 10 mg/mL, the second is 1 mg/mL, and the third is 0.1 mg/mL. For a 1.00 mL mixed volume at each step, a simple 1:10 mixture uses 0.10 mL from the preceding solution and 0.90 mL diluent. The cumulative factors are 10, 100, and 1,000.
Volume planning needs one extra distinction. An intermediate tube may contain 1.00 mL immediately after mixing, but transferring 0.10 mL from it to the next tube leaves only 0.90 mL available. The last tube retains its full mixed volume until a sample is removed. If the protocol requires the full stated volume to remain in every intermediate tube, prepare additional volume that accounts for the next transfer, container dead volume, replicate wells, and expected handling loss.
Check each tube before using the series
Divide the preceding concentration by the displayed step factor; it should equal the next concentration within rounding. Divide the original concentration by each displayed concentration to recover that tube’s cumulative factor. For volume, transfer volume plus diluent volume should equal the stated mixed volume. These checks catch a reversed factor, skipped tube, or confusion between a per-step and overall dilution.
Use unrounded values for planning and round only to volumes the selected equipment can actually deliver. Rounding every intermediate concentration and then using those rounded figures can make the final tube drift from the intended target. Label tubes before transferring, mix each tube as the protocol requires before taking the next aliquot, and consider error propagation: an early pipetting or mixing error affects every downstream dilution.
Scope, safety, and private calculation
The calculator models ideal concentration and volume ratios. It does not account for density changes, chemical reaction, adsorption, degradation, incomplete mixing, biological viability, contamination, matrix effects, pipette uncertainty, or non-additive volumes. It also does not determine whether the starting material, diluent, concentration, or handling procedure is safe. Follow the current laboratory, clinical, educational, or product protocol and use trained supervision for hazardous or biological materials.
The values are calculated in the current browser tab. NexaCurrent does not upload the quantities, formulas, chemical names, element choices, or other information entered here, and no account is needed. Copying is a deliberate action after the answer and working are visible. Refreshing or leaving the page clears the current calculation, so keep a copied result if it is needed for later study.