RandoziWeighted Budget Splitter
Enter a total and give each line a name and a weight, such as 50, 30 and 20. You get each line's part to the cent (or another unit), with the leftover cents handed out by a fixed rule so the parts add up to the total exactly.
| Line | Weight | Part | % of weights |
|---|---|---|---|
| Rent | 50 | 500.00 | 50 |
| Food | 30 | 300.00 | 30 |
| Savings | 20 | 200.00 | 20 |
The parts add up to 1,000.00, exactly the total.
Each part is the total × the weight ÷ the sum of the weights, rounded down to the smallest unit. The units left over go one by one to the lines with the largest remainders; on a tie the line higher in the list comes first. Weights can be decimals, and a weight of 0 gives a part of 0.
Nothing you type leaves your browser. The page splits an amount; it does not check taxes, fees or any rule that applies to your money.
How it works
- Enter the total amount and pick the smallest unit: 0.01, 0.1 or 1.
- Give each line a name and a weight. Add or remove lines as needed.
- Read the part of each line, its share of the weights, and the check that the parts add up to the total.
- Copy the summary, one line per part.
What people use it for
Sharing a joint expense
Split a 1,200 bill between partners in proportion to their incomes, without losing a cent to rounding.
Dividing a project budget
Spread a budget across teams by weight and see each team's part to the cent.
Sharing tips or a prize pool
Divide a pool by hours worked or points scored, with decimal weights if you need them.
Questions
- How is each part computed?
- Each part starts as total × weight ÷ sum of the weights, rounded down to the smallest unit. The units that are left over go one by one to the lines with the largest remainders, so the parts add up to the total exactly. For 100 shared in weights 1, 1, 1 you get 33.34, 33.33 and 33.33. The calculation runs on whole numbers of the smallest unit, so there is no floating-point error, even for very large totals.
- Why does one line get the extra cent, and can I change it?
- When two lines have the same remainder, the line higher in the list comes first. It is a fixed rule, so the same entries always give the same answer. Every part stays within one unit of the exact figure. To choose which of the tied lines gets the extra unit, move that line up the list.
- Can I use percentages as weights?
- Yes. Only the proportion between the weights matters, so 50, 30, 20 and 5, 3, 2 give the same split, and the weights do not have to add up to 100. The last column shows each weight as a percentage of the sum of the weights. A weight of 0 gives a part of 0.
- What are the limits?
- Up to 20 lines, a total up to 1,000,000,000,000 and weights up to 1,000,000,000,000 with at most 9 decimals. The total cannot have more decimals than the smallest unit, and a negative total or weight, or weights that are all 0, are refused with a message. The page only does the arithmetic: it knows nothing about taxes, fees or any legal or contractual rule for sharing money.