Cell Seeding Calculator
Calculate cell seeding density by culture vessel area.
Vessel area: 75 cm²
Learn more
What it does
Cell seeding density is the number of cells you plate per unit surface area (cells/cm²). It sets how crowded cells are when they attach, which strongly affects growth rate, differentiation, and experimental reproducibility. The right density depends on cell line and purpose: routine passaging targets 20–80% confluence by the next day, while differentiation protocols often specify exact densities because crowding directly changes cell behavior.
How it works
Total cells needed = target density (cells/cm²) × vessel area (cm²) × number of vessels. Stock volume = total cells ÷ stock concentration (cells/mL). Diluent volume = final media volume − stock volume. Vessel areas are fixed per plate/flask (e.g. 6-well ≈ 9.6 cm²/well, T-75 ≈ 75 cm²). Always confirm the growth area from the vessel manufacturer's datasheet — '6-well' areas vary between brands (roughly 9.4–9.6 cm²) and the error propagates linearly into your cell count. Count viability with trypan blue and seed based on live cells.
Worked example
Seed a 6-well plate at 1×10⁵ cells/cm². One well area ≈ 9.6 cm² → 9.6×10⁵ cells per well. With a 1×10⁶ cells/mL stock, add 0.96 mL stock + 9.04 mL media for a 10 mL final volume. If your count shows only 80% viability, divide by 0.8 when taking the stock volume: you need 1.2 mL of a 1×10⁶ cells/mL stock to deliver 9.6×10⁵ live cells.
When to use it
Use it when passaging cells, setting up transfection or differentiation assays, comparing treatments at equal confluence, and standardizing seeding across replicates. It is equally useful for 96-well assays, where per-well areas are small (≈0.32 cm²) and pipetting errors are proportionally larger, and for scaling an experiment between plate formats.
FAQ
- What vessel areas does the calculator use?
- It uses standard culture-ware areas: 96-well ≈ 0.32 cm²/well, 24-well ≈ 1.9 cm², 12-well ≈ 3.8 cm², 6-well ≈ 9.6 cm², T-25 ≈ 25 cm², T-75 ≈ 75 cm², T-175 ≈ 175 cm². Pick your vessel from the list and the area is applied automatically.
- How do I calculate total cells from density?
- Total cells = target density (cells/cm²) × vessel area (cm²) × number of vessels. For a 6-well plate at 1×10⁵ cells/cm², one well needs 9.6×10⁵ cells.
- How do I work out the stock volume?
- Stock volume = total cells needed ÷ stock concentration (cells/mL). If you need 9.6×10⁵ cells and your stock is 1×10⁶ cells/mL, use 0.96 mL of stock.
- Why does seeding density matter?
- It controls how quickly cells reach confluence and how they behave. Too dense and cells senesce or differentiate; too sparse and growth stalls. Matching density across replicates keeps experiments comparable.