Project the future value of daily round-up savings compounded over years.

Round up to the nearest pound on a handful of transactions a day and you might sweep 1 daily, roughly 365 a year. At a 5% annual return compounded over 20 years, that builds to around 12,070 — from money you wouldn't have missed.

How to use it

Estimate how much you round up per day on average — most people land at 50p to 2 depending on transaction volume. Set the annual return rate based on where the round-ups land (easy-access savings, a stocks & shares tax-advantaged savings account, a regular saver). Pick a time horizon.

What the result means

The primary figure is the future value of all your daily round-ups, compounded annually. The breakdown shows total contributions versus growth, so you can see how much came from you versus the return.

Why the return rate matters so much

At 2%, daily round-ups of 1 over 20 years grow to roughly 8,900. At 7%, the same contributions reach about 16,000. The rate chosen is the single biggest lever — but returns in equities are volatile, and you shouldn't assume 7% is low-risk.

Quick example

With average daily round-ups of 1 and annual return rate of 5% (plus years of 20 years), the result is 12,069.07. Change any figure and watch the output shift — it's often more useful to see the pattern than to memorise the formula.

Which inputs matter most

You enter Average Daily Round-Ups, Annual Return Rate, and Years. Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.

What's happening under the hood

Annual contribution equals daily round-up times 365. Future value uses the ordinary annuity formula with contributions treated as end-of-year for simplicity. Real round-up products compound more frequently than annually, but the annual approximation is within a few percent for typical round-up sizes. The formula is listed in full below. If the number looks off, you can retrace the calculation by hand — that's the point of showing the working.

Turning the result into a plan

A projection is just a starting point. The real work is setting the monthly amount aside automatically so the saving happens before you can spend it. Most people who hit savings goals set up a standing order on payday; most who miss them rely on willpower at month-end.

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 is a direction of travel, not a guarantee.