Hi twofoofers!

The USDA Database is probably the right resource for you. We have it at the top of the page under Low-Carb Tools, but the actual online database would be better suited to what you are looking for.

Here's an example under the listing of Tomatoes, red, ripe, raw, year round average:

1 cup cherry tomatoes = 149 grams
1 cup, chopped or sliced = 180 grams
1 Italian tomato = 62 grams
1 cherry = 17 grams
1 large whole (3" dia) = 182 grams
1 medium whole (2-3/5" dia) = 123 grams
1 slice, medium (1/4" thick) = 20 grams
1 plum tomato = 62 grams
1 small whole (2-2/5" dia) = 91 grams
1 slice, thick/large (1/2" thick) = 27 grams
1 wedge (1/4 of medium tomato) = 31 grams
1 slice, thin/small = 15.0 grams

You check off the boxes beside them and it gives you the nutritional information on the items you've selected.

Here's the link:
USDA Database

HTH,

Karen