Savings Growth Projection Calculator

Who this is for

A savings pot projected a year at a time. Start from what is there now, add what you put in each month at the rate you expect, and the sheet shows the balance at the end of every year. It also finds the first year the pot reaches a target you set.

Savers deciding how much to put away each month, people checking whether a goal is realistic in the time they have, and anyone comparing a higher deposit against a longer wait.

What this helps you track

• The balance at the start and end of each year
• How much of the growth comes from deposits and how much from interest
• The first year the pot reaches your own target
• The total paid in over the years you choose

How to use it

1. Name the account and enter the opening balance, the monthly deposit and the rate you expect in your own words.
2. Enter the number of years to project and, if you have one, the target you are saving towards.
3. The browser and the workbook run each year for you; on paper, follow the method in the note under the table.
4. Read the final balance from the closing column in your last year and the first year at target from the summary, then try a different deposit or rate.

Formats

• Printable PDF (A4 and US Letter)
• Fillable PDF with form fields
• Fill in online, saved in your browser
• Excel / Google Sheets workbook

The printable is laid out inside a box that fits both A4 and US Letter, so the two files are identical and neither one is scaled. The fillable PDF has real form fields. The workbook uses plain formulas only — SUM, IF, COUNTIF and the like — so it opens in Excel, LibreOffice and Google Sheets without anything breaking, and every calculated cell is grey so you can see which figures it worked out.

How to print

Download the A4 or US Letter file to match the paper in your printer, open it in a PDF reader and print at 100% — not "fit to page", which shrinks the writing space. Both files leave a 14 mm margin, which clears the unprintable edge on home printers. To print the online version with your entries in it, use the Print this sheet button, which prints only the sheet and none of the page around it. More on printing.

Questions

What rate should I use?

The one you expect, from your own account or a rate you want to test. The sheet supplies none. Running it twice, once at a cautious rate and once at a hopeful one, shows the range more honestly than a single figure.

How is the growth worked out?

Each year's growth is your rate applied to the opening balance plus half of that year's deposits, since deposits arrive through the year. It is a simple estimate; your provider's figures will differ with how and when it pays interest.

Does it allow for tax or inflation?

No. The figures are before any tax on interest and in today's money. If you want to allow for either, use a lower rate of your own choosing and label the sheet.

What if the target is more than twenty years away?

The table stops at year twenty, but the first year at target in the summary is worked out directly from your figures, so it still gives the year. It shows 0 when no target is entered or the pot is already there.

Can I add a lump sum in one year?

Not on this sheet, which keeps the deposit the same every year so the summary can be worked out directly. For a lump sum, add it to the opening balance and run a second sheet from that year.