As a general guide:
2 oz / 50g tins = pint Mason jars (16 oz)
4 oz / 100g = 1/2 quart (2 pints, 32 oz) jar
Once you open a tin, your best bet is emptying it into the jar for a decent seal. If you're striving for aging, leave it in the tin; or if it's in bulk, seal it under sanitary...