Cell seeding density calculator
Work out the suspension and medium to seed a plate or flask at a target density.
Nominal growth areas. They differ a little between manufacturers and more between surface treatments, so check the catalogue if the density has to be exact.
From a haemocytometer count or a cell counter.
Covers what stays in the reservoir and the pipette.
Suspension into the master mix
Make up to 16.5 mL with 13.33 mL of medium, then dispense 2.5 mL per vessel.
Cells per vessel
480000
Cells per cm²
50000
Seeded at
192000/mL
3170000 cells needed in total · 6.6 vessels-worth prepared
cells/vessel = density × area; V_suspension = cells ÷ stock; V_medium = V_total − V_suspension- Basic techniques for mammalian cell tissue culture — Current Protocols in Cell Biology, 1998
The count you start from carries its own uncertainty — a haemocytometer read to 100 cells is good to about a fifth, and that error passes straight through to the density seeded here. Where the seeding density matters, count enough cells to earn the precision you are assuming.
When to use this
Use this to turn a seeding density into the volumes you actually pipette, for one vessel or a whole plate. It offers a master mix route and a per-vessel route because they are different jobs, and it catches doses too small to pipette reliably.
Worked example
Seeding a 6-well plate at 5 × 10⁴ cells/cm² from a 1 × 10⁶ cells/mL suspension.
- Vessel
- 6-well plate, 9.6 cm² per well
- Target density
- 5 × 10⁴ cells/cm²
- Suspension
- 1 × 10⁶ cells/mL
- Wells + overage
- 6 wells, 10%
Result
Dispense 2.5 mL per well from that master mix and every well matches.
What people get wrong
- Dosing each well separately across a plate. Small per-well volumes scatter the density; a master mix dispensed evenly is what makes a plate uniform.
- Forgetting overage. Without it the last well gets whatever is left in the reservoir, which is always short.
- Mixing up cells per cm² and cells per well. They differ by the growth area, which is 0.32 cm² for a 96-well and 175 cm² for a T175.
Questions
+Cells per cm² or per well?
Publications quote per cm² because it transfers between vessel formats. The tool accepts either and shows the conversion.
+How much overage should I allow?
Ten per cent is the usual allowance for a plate. More if you are using a multichannel pipette and a reservoir, where dead volume is larger.
+What if the volume needed is under a microlitre?
Dilute the suspension first and take a measurable volume. The tool warns when a dose falls below what a pipette delivers accurately.
Related tools
- Haemocytometer calculator — Turn a chamber count into cells per millilitre, with the counting error stated.
- Dilution calculator — Work out how much stock and diluent to combine for a target concentration.
- OD600 calculator — Convert optical density to cell density and plan culture dilutions.
Science last reviewed .