Cell Viability Calculator

Cell viability is the proportion of healthy, living cells in a sample — a critical quality check before any cell-based experiment or therapy. Enter your live cell count, dead cell count, dilution factor, large squares counted, and hemocytometer factor into the Cell Viability Calculator to get your cell viability %, viable and total cell concentration, cytotoxicity, and viability status. Optionally, add your original suspension volume to calculate total cell number. Also try the find Specific Growth Rate (μ) with Monod Growth Kinetics Calculator.

Results

Cell Viability

Viable Cell Concentration

Total Cell Concentration

Cytotoxicity

Viability Status

What is a cell viability calculator?

A cell viability calculator is a tool that determines the percentage of living cells in a population by analyzing counts of viable and non-viable cells, typically obtained through methods like Trypan Blue exclusion assay. See also our Cell Dilution Calculator (C1V1=C2V2).

How do I count live and dead cells using Trypan Blue?

Mix your cell suspension with Trypan Blue dye (usually 1:1 ratio). Live cells exclude the dye and appear bright/unstained, while dead cells take up the dye and appear blue. Count both types in hemocytometer squares under a microscope.

What is a good cell viability percentage?

Generally, >90% is considered excellent, 80-90% is good, 70-80% is fair, and <70% is poor. However, acceptable viability depends on your specific cell type and experimental requirements.

What dilution factor should I use?

The dilution factor depends on your cell density. For Trypan Blue, typically use 1:1 (dilution factor = 2) or 1:2 (dilution factor = 3). Higher cell densities may require greater dilutions for accurate counting. You might also find our use the Antibiotic Zone of Inhibition Calculator useful.

How many hemocytometer squares should I count?

Count at least 4-5 large squares (1mm x 1mm each) for statistical accuracy. If cell density is very low or high, adjust accordingly. Aim to count 100-200 total cells for reliable results.

What does the hemocytometer factor represent?

The hemocytometer factor converts your cell count per square to cells per mL. The standard factor is 10,000 (10⁴), which accounts for the chamber depth (0.1mm) and converts to cells/mL.

Can I use this calculator for other viability assays?

This calculator is primarily designed for direct cell counting methods like Trypan Blue. For MTT, alamarBlue, or LDH assays, you'll need specialized calculations based on optical density or fluorescence measurements.

Why is my calculated concentration different from expected?

Check your dilution factor, number of squares counted, and hemocytometer factor. Also ensure you're counting the correct chamber area and that your cell suspension is well-mixed before sampling.