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Cell Seeding Calculator (Cells per Well and Seeding Density)

Enter your cell count and how many cells you want per well (or a density in cells/cm²), pick the plate and the number of wells, and get the volume of cell suspension and medium to add.

Inputs

cells/mL

Type 1e6 for 1×10⁶

Target per well

cells
mL

Results

Total cells
1,320,000
Cell suspension to take
1.32 mL
Medium to add
11.88 mL
Total volume
13.20 mL

Common plate formats

PlateArea per wellTypical volume per well
6-well9.5 cm²2 mL
12-well3.8 cm²1 mL
24-well1.9 cm²0.5 mL
48-well0.95 cm²0.3 mL
96-well0.32 cm²0.1 mL

Typical values for Corning flat-bottom culture plates. Brands differ slightly, so check your datasheet when precision matters. Choosing a plate fills in its full well count and typical volume.

Formula

Cells per well = Density (cells/cm²) × Well area (cm²)

Suspension (mL) = Cells per well × Wells × 1.1 ÷ Conc. (cells/mL)

Medium (mL) = Volume per well (mL) × Wells × 1.1 − Suspension

Tip: Without the 10% extra, drop the × 1.1. You can type 1e6 for 1×10⁶ cells/mL.

You got this step right, but a whole experiment has dozens of linked parameters. Change one dilution factor and everything downstream has to be recalculated. In Vara the parameters of your whole experiment are connected, so changing one recalculates the rest automatically. Manage 3 experiments for free.

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FAQ

How much suspension do I need for 5×10⁴ cells per well in a 24-well plate at 1×10⁶ cells/mL?+
With 10% extra, plan for 26.4 wells: 5×10⁴ × 26.4 = 1.32×10⁶ cells, so 1.32×10⁶ ÷ 1×10⁶ cells/mL = 1.32 mL of suspension. At 0.5 mL per well the total is 13.2 mL, so add 11.88 mL of medium, mix, and dispense 0.5 mL into each well.
How do I convert a seeding density (cells/cm²) into cells per well?+
Cells per well = density × well area. A 96-well plate well is about 0.32 cm², so at 1×10⁴ cells/cm² each well gets 3200 cells. Seeding by density keeps confluence consistent when you switch plate formats.
What is the growth area of each plate format?+
Typical values: 6-well about 9.5 cm², 12-well about 3.8 cm², 24-well about 1.9 cm², 48-well about 0.95 cm² and 96-well about 0.32 cm². Brands differ slightly, so check your plate's datasheet when precision matters.
Why add 10% extra?+
Liquid clings to tube walls and tips, so the last few wells often come up short. Preparing 1.1 times what you need makes sure every well gets its full amount. If your cells are scarce, untick the option and prepare for the exact number of wells.
What if the suspension volume comes out larger than the total volume?+
Your suspension is too dilute to reach the target by dilution alone. Spin the cells down, resuspend them in a smaller volume of medium, count again and recalculate.
Should I use the viable cell count?+
Yes. Trypan blue and most automated counters report both total and viable cells. Seed based on viable cells so each well gets the number of healthy cells you planned for.

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