Shared budget split calculator
Splits a shared amount between people equally or in proportion to income.
Fill in the fields and the result will appear here automatically.
Takes one amount and divides it between people equally or in proportion to income. Each line contains a name and an income: the last number is income and everything before it is the name, so names may contain spaces. Whole cents are allocated by largest fractional remainders: even five cents split ten ways cannot produce a negative contribution. The table checks all contributions against the rounded total budget.
How it works
Formula and logic
Equal split: the ideal share is the total divided by the participant count. Income split: total × individual income / combined income. Round the total to cents, then round each ideal share of cents down. Distribute the remaining cents one at a time to the largest fractional remainders; ties follow line order. This preserves the total without negative contributions.
Example
60,000 split between incomes of 80,000 and 120,000 comes to 24,000 and 36,000.
Fields and units
- Amount to split — $
- Participants: name and income per line — name and income in one monetary unit
- How to split — list option
How to use
- — Enter the amount you need to split.
- — List the participants one per line: a name and an income. Write each income as one number without spaces between digits.
- — Choose whether to split equally or in proportion to income.
- — Check the table: the contributions add up to the amount exactly.
Method and limitations
- Calculation method
- Formula and logic
- Limitation
- This allocates a total rather than deciding fair obligations. The total is rounded to one hundredth of the currency unit and must contain at least one such unit; its count must be an exactly representable safe integer. Each income is one number without thousands separators.
FAQ
Who receives the rounding remainder?
Round ideal shares of cents down, then give the remaining cents to the largest fractional remainders. Ties use line order. A hundred split three ways gives 33.34, 33.33 and 33.33; five cents split ten ways gives the first five one cent each and the others zero.
Can I split equally without entering incomes?
Enter any non-negative income number: equal mode ignores its weight but still displays the numerical income in the table. The line format remains name followed by one number.
What if someone earns nothing?
In equal mode that is fine. In proportional mode a person with zero income gets a zero share, and if everyone earns nothing the calculation stops rather than dividing by zero.
Can names contain spaces?
Yes. Only the last number on the line is read as the income; everything before it is the name, so «John Smith 90000» parses correctly.
Is this the same as a 50/30/20 budget?
No. That one splits one person's income between categories of spending. This one splits one amount between several people.