What's the fairest way to split a hotel room between three people?
One room, two beds, three people. Someone's on the floor or paying differently. Here's the maths that doesn't ruin the trip.
Three people, two beds, one hotel bill. The unfairness is structural: someone gets the floor (or the sofa-bed, or shares with a stranger-snorer), so a flat third-of-the-cost split isn't actually fair. The best approach is to weight by sleeping situation: the worst sleep pays the least. It usually works out at roughly 40/30/30 in favour of whoever drew the short straw. Agree the split before booking, write it down, and never re-litigate once you've checked in.
Steps
Worked example
Three friends, two nights in Lisbon, €240 room
Anna, Ben, Cara pick a queen + a single-rollaway room. Cara takes the rollaway. Two nights at €120 = €240. Split with weights Anna 1, Ben 1, Cara 0.7 → Anna €88.89, Ben €88.89, Cara €62.22. EvenRound rounds to €89 / €89 / €62. Cara saved €18, the bed-sleepers absorbed €9 each.
Three-person hotel rooms are always a little awkward. The 0.7× multiplier is the simplest fair rule — and the rotation pattern keeps a long trip honest.