Dressings syn values, converting grams to ml - help?

Hiya

I am confused, can someone help? I've been on the SW site to try and work out syn values of Tesco Balsamic dressing (I can only find light choices or finest listed and its neither)

I have input all the nutritional info carbs, fat, protein per 100g as it says on the bottle but on the website it asks for the portion size in grams (g) well the bottle size is 250ml.

How do I covert 250ml to grams (g)? or is it a straight swop 250ml=250g

Any advice helpful as I haven't a clue

Thanks

No need to use the calculator you can just work it out from the calories - 1 syn for every 20 calories as there is no free food allowance on things like this.

But otherwise a straight mls to g conversion will usually do.