Savings Goal Calculator

Turn "save more" into a dated plan

Vague intentions like "I should save more" rarely stick. A specific, dated goal—$20,000 for a down payment by next summer—gives you a number to hit and a deadline to hit it by. This calculator works either direction: tell it your deadline and it finds the monthly contribution, or tell it the contribution and it finds the finish date.

How the calculator works

Think of your savings as two piles that grow together: money you already have, and money you add every month. Both earn interest along the way. The calculator figures out either the monthly deposit you need, or how many months your current deposit will take—using the same growth logic either way.

Example walkthrough

Same defaults as the tool: $20,000 goal, $2,000 already saved, 24 months, 4% APY.

① Grow what you already have
   $2,000 sitting for 24 months at 4% → about $2,166

② How much is still missing?
   $20,000 goal − $2,166 grown balance → about $17,834 left

③ Spread the gap across 24 monthly deposits (with interest)
   $17,834 ÷ 24, adjusted for compounding → about $715/month

④ Does it add up?
   ~$17,160 you put in + ~$840 interest earned ≈ $20,000 goal

• Step 1 asks what your current balance becomes if it just sits and earns interest—no new deposits yet.
• Step 2 subtracts that from your goal. That gap is what your monthly savings still need to cover.
• Step 3 is the answer the tool shows in “How much per month?” mode: the deposit that closes the gap on time, accounting for interest on each contribution.
• Step 4 is the sanity check—your deposits plus interest should land on the goal. Interest is a bonus; most of the balance still comes from what you save.

The other direction

In “How long will it take?” mode, the calculator does not solve a formula upfront. It walks forward month by month: add your deposit, apply a little interest, check the balance, repeat until you hit the goal (or conclude the contribution is too low). That is why the chart shows a calendar timeline rather than abstract month numbers.

Behind the scenes (optional)

monthly rate  = APY ÷ 12 ÷ 100
grown savings = current × (1 + rate)^months
from deposits = monthly × ((1 + rate)^months − 1) ÷ rate
goal          ≈ grown savings + from deposits

If APY is 0%, the math simplifies to straight division—goal minus current, spread evenly across the months. The formulas above are the compact version of the walkthrough; you do not need them to use the tool.

The quiet power of compounding

Money sitting in a no-interest checking account loses ground to inflation. The same balance in a high-yield savings account earning 4% grows on its own, and that growth compounds—interest earns interest. Over a short goal the effect is modest; over five or ten years it can cover a meaningful slice of the target without a single extra dollar from you.

Pay yourself first

The most reliable savers automate the transfer on payday, before the money can be spent. Treat your monthly contribution like a fixed bill rather than a leftover, and start with a small emergency fund as your first goal so a surprise expense never derails the plan.