How many grams is a quarter cup of chocolate chips?

A quarter cup of chocolate chips (semisweet chocolate chips) weighs

46g

That's 1.6oz. In a 250ml metric cup it's 48g.

This uses the US cup, the size American recipes mean. A quarter cup is 59ml by volume.

Other amounts of chocolate chips

1 cup: 182g
Half a cup: 91g
1 tablespoon: 11g
Full table for chocolate chips

Where these numbers come from

USDA FoodData Central, SR Legacy, food 19080: “Candies, semisweet chocolate”. USDA lists these household measures for it:

1 serving = 14.5g
1 cup large chips = 182g
1 cup mini chips = 173g
1 oz (approx 60 pcs) = 28.35g
1 cup chips (6 oz package) = 168g

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.