six days split between venice and florence in february

I’d keep it 3, 3, and 4. I consider Venice to be endlessly fascinating, and if it’s your point of arrival, you’re going to lose some of that time to jet lag.

I like Inbsig’s suggestion 3, 3 and 4 especially if time is limited in these cities. I do like the idea of starting in Venice and flying out of Rome. 3 great cities!

Hi Michael -
First things first? Don't count your time by DAYS. How many NIGHTS will you have in each place? It makes a difference.

2 nights usually equals 1.5 days of sightseeing,
3 nights usually equals 2.5 days.

That's because arrival day is always a partial - and a jet-lagged one at that - and any physical change of location involves packing up, checking out, getting to a station, sitting on a train, finding your next accommodation and checking in and settled. It eats time.

But how many nights to give each place depends on how those destinations 'speak' to you. 3 nights for Venice is great if that's your entry point to Italy; you'd have two FULL days to fully get over any jet-lag and do some exploring.

Whether to spend 3 nights in Florence depends on what interests you there? 3 nights only gives you 2.5 sightseeing days so that doesn't leave much for Florence itself if taking one of them to leave town. Personally? I would spend it ALL in Florence but you haven't given us any idea of what you'd like to do/see in Italy? If not big on Renaissance art, architecture and history, then maybe Florence isn't your gig whereas I could care less about wine country, especially in winter. Different strokes, and that's OK 'cause it's YOUR trip and YOUR $$$ :O)

4 night/3.5 sightseeing days for Rome is fine. You'll only scratch the surface but it's an OK amount to scratch with.

EDIT: already in europe so will not have any jet lag issues

Ah! This makes a difference. What time will you arrive in Venice? If early in day you probably could get away with 2 nights here.
I love Venice, been twice- and still have not seen everything there, so I don't agree that you can "see pretty quickly"- the major sights, sure, but Venice is more than that.

Could add the night to Florence- you then have so many possibilities for day trips- or not- weather permitting. Lucca, Siena, San Gimigiano, etc- IF a visit to a smaller hill town interests you. There is plenty to do indoors in Florence if weather is inclement and a day trip by bus/train doesn't need to be planned in advance. If art/architecture/history is not your thing- 3 nights in Florence is probably fine.
Also consider that museums in Florence are closed on Monday.

Or
Add it to Rome, plan to return and give Florence/Tuscany a bit more time next trip.
You'll never run out of things to see/do in Rome.

If you are interested in the artistic heritage of Florence then 2 days is not enough which is what you have with 3 nights. If it were me I'd probably do 2 nights Venice and 4 Florence and Rome.