Free Shared Bill Split calculator with clear step-by-step results.
Splits a bill into its standing charge, which everyone pays equally because it accrues whether or not anyone is home, and its usage component, which is allocated by your share of consumption and prorated for days you were away. The comparison against an equal split shows whether the fair figure is worth arguing for.
Your fixed share
Fixed = bill x standing charge share / people
Your usage share
Usage = bill x (1 - standing charge share) x your usage share x presence factor
It is a charge for having the connection at all, which benefits everyone equally regardless of usage or presence. Only the consumption element should vary.
For electricity, count devices and hours; for water, occupancy and habits. If nobody can agree, defaulting the usage share to an equal per-head figure is often the pragmatic answer.