How many grams is half a cup of graham cracker crumbs?

Half a cup of graham cracker crumbs weighs

42g

That's 1.5oz. In a 250ml metric cup it's 44g.

This uses the US cup, the size American recipes mean. Half a cup is 118ml by volume.

Common in American cheesecake bases. UK recipes use crushed digestives instead, but USDA doesn't measure those.

Other amounts of graham cracker crumbs

Where these numbers come from

USDA FoodData Central, SR Legacy, food 18173: “Cookies, graham crackers, plain or honey (includes cinnamon)”. USDA lists these household measures for it:

1 oz = 28.35g
1 cracker = 15g
1 cup, crushed = 84g
1 large rectangular piece or 2 squares or 4 small rectangular pieces = 14g

Fractions of a cup are the cup weight scaled down. The tablespoon figure is the cup weight divided by 16, since USDA doesn't list a tablespoon for this ingredient. The teaspoon is a third of the tablespoon. Metric-cup figures assume a 250ml cup, and Australian tablespoons hold 20ml. Weights under 10g are rounded to 0.1g, everything else to the nearest gram. Full source list.