Monthly Savings Needed Calculator

How it works

Reaching a savings goal is a race between three things: the money you have already put away (which quietly grows on its own), the deposits you add each month, and the interest both of them earn. This calculator works out how much your current savings will grow by themselves, then solves for the monthly deposit that covers whatever gap is left, assuming deposits at the end of each month with interest compounded monthly:

• M — the monthly deposit you are solving for
• G — your goal
• P — what you have already saved
• i — monthly interest rate (annual rate ÷ 12)
• n — number of months

With the defaults above, $5,000 grows to about $6,105 on its own over 5 years at 4%, leaving roughly $18,895 for your deposits to cover. The monthly amount that gets there, deposits plus the interest they earn, is about $285 a month.

✓ Every result is checked against independent reference math. See how we test the calculators →

A worked example: $25,000 in five years

You want $25,000 in five years and already have $5,000 set aside, earning 4% a year. Plug those numbers in and the calculator says you need to save $285/month, which is about $65.77 a week.

Here is where that lands. Your starting $5,000 does some of the work, your monthly deposits add up to $17,100 over the 60 months, and interest earns you $2,900 on top. Add it together and your balance hits $25,000 right around July 2031.

The return you assume matters a lot. Park the money in index funds at 7% and you only need $250/month. Leave it in cash at 0% and it climbs to $333/month, a gap of $83 every month for the same goal.

Swap in your own goal and timeline to see your number.

Three ways to lower the monthly number

• Give it more time. A longer deadline spreads the same goal across more deposits and lets compounding do more of the lifting. Even one extra year makes a visible dent.
• Start from a bigger base. Every dollar already saved grows the whole time, so a one-time top-up early on shrinks the monthly figure more than the same dollar added later.
• Pick the right home for the money. A few extra percent of return compounds meaningfully over years. Match the account to the timeline: safe and liquid for near-term goals, growth-oriented for far-off ones.

A worked example with a bigger goal

Swapping in different numbers shows how the monthly figure responds. Say you are saving for a $40,000 home down payment, you already have $8,000 put away, you want it ready in four years, and the money sits in a high-yield savings account at 4%. Your $8,000 grows to roughly $9,390 on its own, which leaves about $30,610 for your deposits to cover.

The monthly amount that gets there lands near $590: your own contributions come to around $28,300, and interest quietly covers the rest.

• Give it more time. Stretch the same goal to six years and the monthly figure falls to about $365, because the target spreads across two more years of deposits and compounds for longer.
• Start from zero. Keep the four-year deadline but remove the $8,000 head start and the number climbs to around $770, since none of your base is doing early work for you.
• Chase a higher return. Hold four years and lift the rate to 7% and the figure eases only to around $535, because over a short horizon interest carries far less of the load than time does.

The pattern holds across almost any goal. Your deadline and your starting balance move the monthly number much more than the return does over short spans, so reach for those two levers before you pin your hopes on markets.

What the monthly figure assumes

The result is only as honest as its inputs, and a few real-world details sit outside the formula. Knowing them keeps you from trusting the number more than it deserves.

• It ignores inflation. The goal is in today’s dollars unless you raised the target to a future price. For a goal several years out, nudge it up or use a slightly lower return so the answer keeps its buying power.
• It assumes you never miss a month. Every skipped deposit has to be made up later, usually at a higher monthly rate. Automating the transfer the day you are paid is the simplest way to keep the plan on its rails.
• It treats the return as steady. Real returns wobble, and a rough stretch near the deadline can leave you short even when the long-run average looked fine. A conservative rate builds in a quiet margin.
• It leaves out tax on interest. In a taxable account, some of the interest shown goes to tax, so the true monthly figure runs a touch higher than the tidy version here.
• It rounds the timeline to whole months. Half-months and the exact day you start get smoothed over, which shifts the figure by pennies rather than dollars on any realistic goal.

None of this makes the number wrong. It just means you should treat it as a confident starting plan rather than a promise, and rerun it whenever your goal, timeline, or income changes.