chris French wrote:
You don't say what veg.
60's will do for things like leeks, onions.
40's will do for a range of things
24's for larger things like marrows etc
The more info you give the better will be your answer

FWIW, for a lot of things (courgettes, melons, sweet peas, sweetcorn) I
would always use root trainers rather than modules.

We grow sweetcorn, peas, beans etc. in Rootrainers, but squashes,
courgettes, etc. tend to grow in smallish pots.

That's probably better, but the root trainers tesselate better. :-)
Seed planting time is always a bit of a, erm, squash.