Catch-Up Savings Calculator

With 20,000 saved, a target of 100,000 in 10 years, and an expected 7% annual return, the existing pot projects to roughly 39,300. The 60,700 gap requires approximately 366 a month in new contributions to close.

How to use it

Enter current savings, target amount, years remaining, and an assumed return rate. Cash savings rates typically range from 2-5%; diversified long-term equity portfolios average 5-8%; higher assumptions carry higher risk.

What the result means

The primary figure is the monthly contribution needed. The secondary rows show the existing pot's projected growth, the gap new contributions must close, and total new money added over the period. If the monthly figure appears high, options include: extending the time horizon, lowering the target, or raising the assumed return (though higher return assumptions carry higher risk of not being met).

What this doesn't model

Inflation. The target is treated as a nominal figure. To account for real purchasing power, reduce the assumed return by an inflation expectation or uprate the target by the same amount.

Run it with sensible defaults

Using current savings of 20,000, target amount of 100,000, years remaining of 10 years, annual return of 7%, the calculation works out to 365.85. The defaults serve as a starting point.

The levers in this calculation

The inputs — Current Savings, Target Amount, Years Remaining, and Annual Return — do not pull with equal force. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.

How the math works

Projects the current pot forward at the annual return, subtracts from the target to find the gap, then solves the ordinary annuity formula for the annual contribution needed to fill the gap and divides by 12 for the monthly figure. Assumes end-of-year contributions and annual compounding.

Turning the result into a plan

A projection is a starting point. Setting the monthly amount aside automatically places savings before discretionary spending. Some people who hit savings goals set up a standing order on payday; patterns suggest those relying on willpower at month-end tend to miss targets.

What this doesn't capture

The calculation assumes a steady savings rate and a stable interest rate. Real saving journeys include emergencies, windfalls, and rate changes — especially in easy-access products. The figure indicates a direction of travel, not a guarantee.