In short
- Your share = bill × your weight ÷ total of all weights.
- The weight can be income, nights or use, depending on the cost.
- Agree on the weight before you spend, and write it down.
- Always check that the shares add up to the total.
Which weight to use for each bill
- Income: for fixed household bills when some people earn a lot more. Use take-home pay.
- Nights: for a trip or a rental where not everyone stays the whole time.
- Use: for things only some people use, like the drinks at a party. If someone didn't use it, their weight is zero.
Not every bill needs the same weight: rent can go by income and groceries can be split evenly. For couples, see couples expenses; to split rent by room size, see splitting expenses with roommates.
Splitting bills based on income: three roommates
Emma takes home $2,000 a month, Jake $3,000 and Priya $5,000, for $10,000 combined. Emma's weight is 20%, Jake's 30% and Priya's 50%. Utilities and shared groceries come to $1,500 this month.
| Person | Weight | Share |
|---|---|---|
| Emma | 20% | $300 |
| Jake | 30% | $450 |
| Priya | 50% | $750 |
$300 + $450 + $750 = $1,500, so it checks out.
Splitting by nights: the beach house
A beach house costs $840 for the week. Luis and Priya stay 7 nights, Jake 4 and Emma 3. That's 21 person-nights, so each one is worth $40 ($840 ÷ 21).
- Luis: 7 × $40 = $280
- Priya: 7 × $40 = $280
- Jake: 4 × $40 = $160
- Emma: 3 × $40 = $120
Total: $840. If it doesn't divide evenly, round and let one person cover the cents.
Do it in Divall
- In Family and roommates, choose the by-percentages agreement (say 20%, 30% and 50%) and every household cost is split that way; rent and utilities add themselves each month.
- In Vacation, mark who was there each day and costs are split by days.
- In Nights out, a group like "drinkers" pays only for its own, and Divall shows who pays whom.
Nights out is free; Family and roommates and Vacation are part of Divall Pro, with a 7-day free trial. Divall is free to start: your next proportional split gets logged without doing the math by hand.
Frequently asked questions
Is splitting by income fairer than splitting evenly?
If you earn about the same, an even split is simplest. If one person earns a lot more, splitting by income means everyone puts in the same percentage of what they take home.
How often should we recalculate the percentages?
Whenever someone's income changes or someone moves in or out. If nothing changes, the same agreement works month after month.