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Rent Split by Room Size Calculator

Rent split by room size, income or equally, with common areas divided equally first. Splitting the whole rent by bedroom size overcharges the large room, because the kitchen and living room are shared regardless.

Also called: split rent by room size, flatmate rent calculator.

$
Split by

One per person.

$
%
Each person pays
20000, 20000, 20000

20000, 20000, 20000. That is 23000, 23000, 23000 once 9,000 of shared bills is divided equally. Split equally, which ignores room size and income entirely.

Rent shares
20000, 20000, 20000
Shared bills each
$3,000.00
If split equally
$20,000.00
Largest share
$20,000.00
Smallest share
$20,000.00
Common area rent each
$0.00
Totals
23000, 23000, 23000
On the method
Split equally, which ignores room size and income entirely.
Method and background

How this is calculated

The common area portion divides equally, since everyone uses the kitchen and living room the same amount, and only the remainder divides by private room size. Splitting the entire rent by bedroom area is the common error and overcharges whoever has the larger room for space they do not exclusively use. Income splitting is a different principle: it divides by ability to pay rather than by what is consumed, which some households prefer and which produces a very different answer.

common areas divide equally and only the private space divides by size, which is what makes a size split fair
a
Room area
C
Common area share

Method and limits

What it assumes

  • Shared bills divided equally, which is the usual arrangement.

What it deliberately does not model

  • Room quality, light and en-suite access matter and are not captured by area alone.
  • An income split is a fairness judgement rather than an arithmetic one.

Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator

Frequently asked questions

Should I split the whole rent by room size?
No. The kitchen, living room and bathroom are used equally, so that portion divides equally and only the private space divides by size. Splitting everything by bedroom overcharges the big room.