Sinking Fund Calculator

Use this calculator to estimate the monthly payment needed to build a sinking fund by a future date.

What this calculator does

The sinking fund calculator finds the regular amount needed to accumulate money for a planned expense.

It uses:

• target amount
• months to goal
• annual interest rate
• monthly compounding

Sinking Fund Formula

PMT = FV x r / ((1 + r)^n - 1)

Where:

• PMT = monthly sinking fund payment
• FV = target amount
• r = monthly interest rate
• n = number of months

Example calculation

If:

• Target amount = 6,000
• Time to goal = 18 months
• Annual interest rate = 3%

Then:

• Monthly payment = about 326
• Total contributions = about 5,868
• Interest earned = about 132

The sinking fund needs about 326 per month.

What is a sinking fund?

A sinking fund is money set aside regularly for a known future expense. It prevents planned costs from becoming sudden cash-flow problems.

Why sinking funds matter

• turns large expenses into monthly amounts
• reduces reliance on debt
• keeps planned savings separate
• makes future purchases easier to manage

When to use this calculator

• saving for annual insurance or taxes
• planning car repairs or home maintenance
• preparing for travel or holidays
• building cash for a known purchase

Common mistakes

• starting too late for the target date
• mixing sinking funds with everyday spending
• forgetting that some goals earn little or no interest
• using one fund for too many unrelated goals

Sinking fund vs emergency fund

A sinking fund is for expected expenses. An emergency fund is for unexpected expenses.

FAQs

What is a sinking fund?

A sinking fund is a dedicated savings plan for a known future cost.

How do you calculate a sinking fund?

Use the target amount, monthly rate, and number of months to find the required recurring deposit.

What is a good sinking fund?

A good sinking fund is tied to one clear expense and funded before the due date.

What is the difference between a sinking fund and emergency fund?

A sinking fund is planned. An emergency fund is reserved for unknown events.