Formulas
US liquid: cups = pints × 2
US dry: cups = pints × 2.3273 (approx.)
Imperial: cups = pints × 2
Why the difference?
US liquid pint is 473 mL and uses the 236 mL cup, so 1 pint = 2 cups. US dry pint is 550.6 mL, so you get a little more than 2 cups from a dry pint. Imperial/UK pint is bigger (568 mL) and imperial cup is bigger (284 mL), so it also works out to 2 cups.
FAQ
1. How many cups in 1.5 pints?
US liquid: 1.5 × 2 = 3 cups.
2. Is 2 pints always 4 cups?
Yes for US liquid and Imperial. For US dry it’s slightly more than 4 cups.
3. Which one should I pick if I don’t know?
Most US online recipes mean US liquid. UK cookbooks and pub-style recipes often mean Imperial.