How to split bills when one of you works from home

An even split on utilities makes sense when both people are out of the apartment the same number of hours. It stops making sense the moment one of you works from home and the other doesn't — the AC runs all day for one person's benefit, the internet carries video calls instead of nothing, and the electric bill quietly becomes a cost one household member is causing more of than the other.

The honest version of “it's not that much more”

It usually is not enough to be worth an argument on its own — a work-from-home setup adds maybe 10-20% to a power bill, not double it. The problem is rarely the dollar amount. It is that one person notices the asymmetry and the other has never had a reason to think about it, and an unspoken imbalance is what turns a $15 difference into a resentment.

A rule that ends the conversation instead of restarting it monthly

• Add a flat percentage to the WFH person's share of utilities — 60/40 instead of 50/50 is a common, defensible starting point, adjustable once you have a couple of bills to look at.
• Or treat it as a real cost and split the difference: compare a bill from a month both of you were mostly out against a typical month, and split that gap the way you'd split rent.
• Whichever you pick, apply it to the utility bill specifically, not to rent. Rent is the same cost regardless of who is home; the electricity is the one that actually moves.

💡This is worth agreeing once, in writing, precisely because it feels too small to formalize. Small recurring asymmetries are exactly what compounds into “I always pay for more than my share” eighteen months in.