TOOLOG / WEB UTILITY
Ratio Split Calculator | Decimal Ratios, Budgets & Rounding
Split budgets or shared revenue by relative or decimal ratios. Check amounts, percentage shares, half-up rounding and the final balance adjustment, then copy the result.
Try the tool
Enter your details below. Results update instantly.
Round half up; the last item receives the remaining balance and may not be a multiple of this unit. Order matters.
Up to 100 items / 10,000 characters. Use name,ratio or ratio only; the last comma separates the ratio. Use a decimal point, up to 12 decimal places, greater than 0 and up to 1 trillion. No exponents or % signs. Blank lines are ignored.
Enter a total and ratios to split the amount instantly.
Split a total amount by ratio
When you need to allocate a budget, profit share, or shared cost by a predefined ratio, the hard part is converting relative weights into exact amounts without losing money to rounding.
This tool helps you quickly calculate:
- each allocation amount
- each item’s percentage share
- rounding by unit
- the final last-item adjustment
How it works
- Add up all ratio values.
- Convert each item into a share of the total.
- Multiply the total amount by each share.
- Apply the selected rounding unit.
- Adjust the last item so the final sum still matches the original total.
That makes it useful for budget planning, settlement, revenue sharing, and cost allocation.
How to use the ratio allocation calculator
- Enter a whole-number total.
- Add up to 100 items, one per line, as
name,ratioor ratio only. - Choose a rounding unit from 1, 10, 100, or 1,000.
- Review each amount and percentage, the allocated total, and the last-item adjustment.
- Copy the result when you need to share or record the allocation.
The calculator starts with an empty result. Load example fills in a complete 5:3:2 allocation, while Clear removes every input and result.
Input format and limits
- Total: a whole number from 1 to 1 quadrillion
- Items: up to 100 non-empty items and 10,000 characters in total, in
name,ratioformat or one ratio per line - Ratio: a positive number no greater than 1 trillion; decimals are accepted
- Rounding: 1, 10, 100, or 1,000 units
If rounded earlier allocations would exceed the total and make the last allocation negative, the tool stops and asks for a smaller rounding unit. Item names and calculations stay in your browser.
Ratio split examples
Example 1: Marketing budget allocation
- Total amount: 1,000,000 KRW
- Ratios: 5, 3, 2
- Rounding unit: 100 KRW
→ Item A: 500,000 KRW → Item B: 300,000 KRW → Item C: 200,000 KRW
Example 2: Profit sharing
- Total profit: 2,350,000 KRW
- Ratios: 40, 35, 25
- Rounding unit: 10 KRW
The calculator converts the ratios into percentage shares, rounds each allocation, and adjusts the last item so the final sum remains exactly 2,350,000 KRW.
Empty results, input errors and copying
- A total must be a whole number from 1 to 1 quadrillion.
- Every ratio must be greater than 0 and no greater than 1 trillion.
- Blank lines are skipped; invalid ratios report the original line number. Use a decimal point, not a decimal comma, and omit
%, exponents and hexadecimal notation. - With empty or invalid inputs, the previous result is cleared and Copy result is disabled. Correct the highlighted input to calculate again.
- If automatic copying is unavailable, select and copy the displayed amounts manually. Processing stays in your browser; copying puts the result on your device clipboard.
- If a large rounding unit would make the final allocation negative, no result is produced; choose a smaller unit and calculate again.
Good companion tools
- For percentage and change calculations: Percent Calculator
- For equal split by people: Split Bill Calculator
- For unit value comparison: Unit Price Calculator
Decimal ratios, half-up rounding and item order
Enter decimal ratios with up to 12 decimal places. For example, 0.3 and 0.1 have the same weights as 3 and 1. Enter 50, not 50%. Exponents (1e-3), hexadecimal and decimal commas are not supported. The last comma separates the name from the ratio. Blank lines are ignored, but error messages keep the original line numbers. Input is limited to 10,000 characters and 100 items.
Allocation amounts use exact integer arithmetic for decimal ratios and round half up. For a total of 2, ratios 0.3:0.1 and unit 1, the first amount rounds from 1.5 to 2 and the last receives the remaining 0. Only percentage displays are rounded to two decimal places; a share below 0.01% displays as <0.01%.
The final item receives the balance after all earlier items have been rounded. Changing item order can change the amounts, and the final amount need not be a multiple of the selected unit. This is not a largest-remainder method for distributing rounding differences fairly.
FAQ
Do I need item names?
No. Names are optional, but using them makes the copied result easier to read.
Do the ratios have to add up to 100?
No. Use relative weights such as 1, 1, 2 on separate lines, or 50, 30, 20 for percentage-style weights without the percent sign. The calculator normalizes their sum.
Is this useful for budget planning?
Yes. It is especially practical when a total budget must be allocated across departments, marketing channels, project partners, or expense categories.
Why is the last item adjusted?
Because rounding can create a small difference. The final item absorbs that difference so the total remains exact.
Can I paste ratios without names?
Yes. Enter values such as 5, 3, and 2 on separate lines and the tool assigns default item names.
Why can a rounding unit be rejected?
If it is too large for a small total, rounding earlier items can exceed the available amount. Rejecting that case prevents a negative final allocation.
Does changing item order change the amounts?
It can. Earlier items are rounded and the last receives the balance, which may not be a multiple of the rounding unit. This is not a fair largest-remainder allocation method.
How do I enter decimal ratios?
Use a decimal point and up to 12 decimal places. Ratios 0.3 and 0.1 have the same weights as 3 and 1. Exponents, hexadecimal and % signs are not supported.