Online Proration Calculator (Rule of Three)

The online proration calculator, a simple and effective tool for performing proportional calculations quickly. Whether you need to split an amount, a rent, a salary or a duration, this calculator is designed to help you get accurate results in a few clicks using cross multiplication.

What is proration?

The term "prorated" comes from the Latin "pro rata", meaning "in proportion". It is a mathematical concept used to distribute a quantity based on the proportion of another quantity. For example, if you need to split rent between several roommates based on the size of their rooms, you use proration to determine how much each one must pay.

Proration calculation example:

Suppose you have a monthly rent of $1,200 to split between two roommates. The first has a 20 m² room and the second a 30 m² room. The total area is 50 m². The first roommate will pay (20 × 1200) / 50 = $480, while the second will pay (30 × 1200) / 50 = $720.

How to use the proration calculator?

Using the proration calculator is simple and intuitive. Here are the steps to follow:

• Enter the individual share (A) in the first field. Example: the room's area.
• Enter the total share (B) in the second field. Example: the total area of the apartment.
• Enter the total value to split (C) in the third field. Example: the total rent.
• The result (prorated amount) is automatically calculated and displayed in the "Result" field.

For example, if you enter 30 in field A, 50 in field B, and 1200 in field C, the calculator displays 720 as the result, which corresponds to the rent share for a 30 m² room out of a 50 m² total.

Practical applications of the proration calculator

The proration calculator is a versatile tool that can be used in many cross-multiplication situations.

For example, it can split rent — ideal for roommates who want to divide the rent based on room size or other criteria. It is also useful for salary calculations, particularly for companies that need to distribute pay according to hours worked or performance. Budget management is easier too, since it helps split a budget between different departments or projects according to their respective needs. Finally, it is handy for time calculations, to divide a period of time between several activities or tasks.

By using this calculator, you save time and avoid calculation errors, ensuring a fair and precise distribution in all your proportional calculations.

Save and export the results

You can save the results of your proration calculations by pressing the Save button. This lets you keep a copy of your results. Then, if you wish, you can export the results in CSV and PDF format.

Keyboard shortcuts:

m ⇝ Clear

f ⇝ Save