Cell Seeding Calculator
Culture Mode
Cell Type & Seeding Density Preset
Current Cell Density (×106 cells/mL) ?
Target Seeding Density (×106 cells/mL) ?
Target Vessel
Working Volume (mL)
Number of Vessels
Pipetting Reserve (%) ?
Tip: Count your cells first with the Cell Counting Calculator, then use that density here.
0.75mL
Cell Suspension per Vessel
14.25mL
Media per Vessel
1:6.7
Split Ratio
4.50×106
Total Cells Needed
0.75 mL
Total Suspension
14.25 mL
Total Media
Vessel Composition — Suspension vs Media
Each bar represents one vessel showing the pipetting plan
Bench Recipe
Step Per Vessel Total (with reserve)

About the Cell Seeding Calculator

This cell seeding calculator (also known as a cell culture split ratio calculator or cell plating calculator) computes the exact volumes of cell suspension and media you need to seed new vessels at a target density. It supports both suspension cultures (calculated from cells/mL) and adherent cultures (calculated from cells/cm²), with presets for every common vessel format: 96/48/24/12/6-well plates, T25/T75/T175/T225 flasks, 125–3000 mL shake flasks, and bench/pilot bioreactors.

The underlying formula is: volume of cell suspension = (target cells per vessel) / (current cell density). For suspension culture, target cells per vessel = target density × working volume. For adherent culture, target cells per vessel = target density (cells/cm²) × surface area. The media volume needed is simply the remaining working volume after the suspension has been added.

The calculator also reports the split ratio automatically. Split ratio = current density / target density, or equivalently, new total volume / suspension volume used. A 1:4 split means 1 part cell suspension is diluted into 4 parts total volume. Typical split ratios for common cell lines: adherent CHO 1:5–1:10, HEK293 1:3–1:10, primary cells 1:2–1:4, iPSCs 1:3–1:6, hybridoma in suspension 1:4–1:10. The calculator flags unusual split ratios (<1:2 or >1:20) so you can catch mistakes before pipetting.

Pair this tool with our Cell Counting Calculator for a complete passage workflow: count cells from the hemocytometer, measure viability, then feed the current density into this seeding calculator to set up the next passage or experimental plate. The CellTrack PWA logs every passage automatically so you can track population doublings, growth rate, and passage history over time.

Related Tools & Articles

Cell Counting Calculator
Hemocytometer counts → VCD, viability %
CellTrack PWA
Log passages, auto-calculate growth rate & doubling time
Doubling Time Reference
CHO, HEK293, Vero doubling times table
Seed Train Planner
Scale up from vial to bioreactor, plan the whole train

Frequently Asked Questions

How do I calculate cell seeding volume?

Cell seeding volume = (target cells per vessel) / (current cell density). For suspension culture at target density Dtarget (cells/mL) in a vessel of working volume V: suspension volume to add = (Dtarget × V) / Dcurrent. Media volume = V − suspension volume. Example: seeding 5 mL at 0.3 × 106 cells/mL from a 2 × 106 cells/mL stock needs 0.75 mL suspension + 4.25 mL media.

What is a cell culture split ratio?

A cell culture split ratio is the dilution factor between the current confluent culture and the new subculture. A split ratio of 1:4 means 1 part cell suspension is diluted into 4 parts total volume. Split ratio = current density / target density. Typical split ratios: adherent CHO 1:5–1:10, HEK293 1:3–1:10, primary cells 1:2–1:4, iPSCs 1:3–1:6, hybridoma suspension 1:4–1:10.

What is a typical cell seeding density?

Typical seeding densities by cell type. Suspension: CHO 0.2–0.5 × 106 cells/mL, HEK293 suspension 0.3–1.0 × 106 cells/mL, hybridoma 0.1–0.3 × 106 cells/mL. Adherent: CHO-K1 1–3 × 104 cells/cm², HEK293 5–10 × 104 cells/cm², HeLa 1–2 × 104 cells/cm², MSCs 5 × 103 cells/cm², iPSCs 2–5 × 104 cells/cm².

How do I plate cells in a 6-well or 96-well plate?

For a 6-well plate (9.6 cm² per well, 2–3 mL working volume) at 5 × 104 cells/cm² you need 4.8 × 105 cells per well. For a 96-well plate (0.32 cm² per well, 100–200 μL) at the same density: 1.6 × 104 cells per well. Our cell plating calculator sizes the exact suspension volume, media volume, and total cells needed for any vessel, accounting for 10–15% pipetting reserve.

How many cells do I need to passage my culture?

Total cells needed = target density × working volume × number of vessels + pipetting reserve. Example: seeding 10 T75 flasks (15 mL each) at 0.3 × 106 cells/mL in suspension needs 0.3e6 × 15 × 10 = 4.5 × 107 cells, + 10% reserve = 5.0 × 107. At a stock of 2 × 106 cells/mL, that is 25 mL of suspension.

What is the difference between cell counting and cell seeding?

Cell counting determines how many viable cells are in your current suspension using a hemocytometer or automated counter. Outputs: cells/mL and viability %. Cell seeding uses that density to calculate how much suspension to transfer into new vessels to achieve a target seeding density. Typical workflow: trypsinise confluent flask → count (cell counting calculator) → seed new vessels (this tool).

How does split ratio relate to seeding density?

Split ratio and seeding density are two ways of expressing the same passage operation. Split ratio = current density / target density. A 1.2 × 106 cells/mL confluent flask split 1:4 starts the new culture at 0.3 × 106 cells/mL. Our cell culture split ratio calculator accepts either input and computes the other automatically.