Identify your dish style (puree/sauce vs. soup/stew vs. salad) and choose the substitute that matches the texture you want.
Use the listed ratio; if the substitute is firmer, mash/blend ⅓ to ½ to mimic butter beans.
Adjust texture with liquid: stir in a little bean cooking liquid, broth, or water until it looks like your target consistency.
Taste and rebalance: butter beans feel mild, so add salt gradually and a small pinch of acid (lemon/vinegar) if the swap tastes flat.
Warm through briefly (2–5 minutes) so the beans absorb seasoning without breaking down too much.