People type this into search every day: how much to save per month for a goal.
The usual answer is “target minus what you have, divided by months.” That is the right starting point. It ignores interest if the money will sit for years, and it hides how hard the monthly number gets when the deadline is close.
This page is a labeled example. It is not a forecast of a bank APY or a fund return, and it is not personalized financial advice.
Turn the goal into a date, or a monthly amount
The CFPB savings plan worksheet does the cash version. Their example is an emergency fund of $1,000 in 10 months. Monthly amount: 1000 ÷ 10 = $100. No interest in that table.
Their goal-setting tool adds the same last step for any goal that needs money: figure out how much to set aside each week or month.
The savings goal timeline calculator keeps that idea and adds an optional return. Each month it multiplies the balance by 1 + annual return ÷ 12, then adds the contribution at the end of the month. Same monthly loop as the compound savings post.
The assumptions are blunt. The return stays constant. Contributions are the amount you can repeat. Fees, taxes, and inflation are excluded.
The published $25,000 example
Here are the defaults:
- already saved: $5,000
- savings goal: $25,000
- monthly contribution: $600
- annual return: 3.5%
Gap today: 25000 − 5000 = $20,000.00
Months: 32, which the calculator prints as 2 years 8 months
Final balance: $25,582.25
Total contributed: 5000 + 600 × 32 = $24,200.00
Estimated growth: 25582.25 − 24200 = $1,382.25
Calculator result
Savings goal timeline
- Already saved
- $5,000.00
- Savings goal
- $25,000.00
- Monthly contribution
- $600.00
- Annual return
- 3.5%
2y 8m
estimated time
- Final balance
- $25,582.25
- Total contributed
- $24,200.00
- Estimated growth
- $1,382.25
$1,382.25 is the modeled growth on this path. Most of the $25,582.25 is still money you deposited.
Fig 1 · 1/2
Where $25,582 comes from
Defaults: $5,000 start, $600 a month, 3.5% for 32 months
Contributed
$24,200.00
Growth
$1,382.25
You put in $24,200.00, almost the whole pile.
Modeled growth is $1,382.25.
1382.25 ÷ 25582.25 = 5.4% of the ending balance. A 3.5% annual rate on a two-year-and-change goal does not do the heavy lifting.
Fig 2 · 1/2
Months to $25,000
Same $5,000 start and $600 a month at 3.5%
Saved now
$5,000
2y 8m
Target date next
$25,582
The $5,000 already saved is 20% of the $25,000 target.
Month 32 lands at $25,582.25.
The monthly amount moves the date more than 3.5% does
Keep the $5,000 and the $25,000. Keep 3.5%. Change only the monthly contribution.
- $300 a month: 4 years 11 months. Final balance $25,220.99. Contributed $22,700.00. Growth $2,520.99.
- $600 a month: 2 years 8 months. Final balance $25,582.25.
- $800 a month: 2 years. Final balance $25,219.98. Contributed $24,200.00. Growth $1,019.98.
Fig 3 · 1/1
Three monthly amounts
Same $5,000 start, $25,000 target, 3.5% return
Months to the target
- Months
| Category | Months |
|---|---|
| $300 / mo | 59 |
| $600 / mo | 32 |
| $800 / mo | 24 |
$300 a month needs 59 months.
$800 a month needs 24 months. $600 sits in between at 32.
The editorial guide on this tool says to change the monthly contribution first when the date is too far. That is the input you control.
If you pick the date first and want the monthly number, the cash formula is still the CFPB one. For a 24-month deadline at 0%, (25000 − 5000) ÷ 24 = $833.33. At 3.5% the monthly loop needs $791.14 to land on $25,000.06 in 24 months. The return shaved $42.19 off each deposit.
Run 0% next to the 3.5% path
Same $5,000, same $600, return set to 0%.
Time: 2 years 10 months (34 months)
Final balance: $25,400.00
Growth: $0.00
Two extra months, because the 3.5% path had $1,382.25 of modeled interest helping.
Fig 4 · 1/2
Three years of the same $600
$5,000 start. One path at 3.5%, one path at 0%.
Balance
- 3.5% monthly
- 0% cash in
| Point | 3.5% monthly | 0% cash in |
|---|---|---|
| 0y | $5.0k | $5.0k |
| 1y | $12k | $12k |
| 2y | $20k | $19k |
| 3y | $28k | $27k |
Year 1 is $12,494 at 3.5% and $12,200 at 0%.
Year 3 is $28,293 at 3.5% and $26,600 at 0%. The target was $25,000.
Year-end balances with the $600 default:
- year 1 at 3.5%: $12,494.47
- year 2 at 3.5%: $20,255.49
- year 3 at 3.5%: $28,292.54
At 0% those years are $12,200.00, $19,400.00, and $26,600.00.
The compound interest post is the same loop over 10 and 30 years, where growth can pass the deposits. A $25,000 goal two years out is not that story.
SEC Investor.gov’s compound interest definition still applies. Interest sits on principal and on interest already earned. On a short cash goal, that effect is small, so a cautious rate is the honest one.
A known bill does not need a return
The sinking fund contribution calculator is the CFPB worksheet with a name. No investment return.
(Future cost − already reserved − expected contributions) ÷ months ÷ contributors
Defaults:
- future cost: $2,400
- already reserved: $400
- expected one-off contributions: $0
- months remaining: 10
- people contributing: 1
Still needed: 2400 − 400 = $2,000.00
Monthly set-aside: 2000 ÷ 10 = $200.00
Already funded: 400 ÷ 2400 = 16.7%
Calculator result
Sinking fund contribution
- Future cost
- $2,400.00
- Already reserved
- $400.00
- Expected one-off contributions
- $0.00
- Months remaining
- 10 months
- People contributing
- 1 people
$200.00
to set aside each month
- Total needed each month
- $200.00
- Amount still needed
- $2,000.00
- Already or externally funded
- 16.7%
Car insurance, a flight, a laptop, and property tax are sinking-fund problems because the date is known. A 3.5% model does not pay the bill if the market is down that month.
The CFPB emergency fund guide wants a specific goal and a consistent transfer. Their savings-planning tool is the same monthly arithmetic.
The emergency fund target defaults need $18,900.00 for six months of essentials, with $6,500.00 already saved. Gap: $12,400.00.
Put that gap through the timeline tool at 0%, because this cash is there to spend.
- $900 a month, the leftover on the budget planner defaults: 1 year 2 months. Final balance $19,100.00.
- $600 a month: 1 year 9 months. Final balance $19,100.00.
Both overshoot $18,900.00 because the loop stops at the first month the balance clears the target.
A long goal is a monthly number, not a date
The child savings goal calculator flips the inputs. You pick the year. It solves for the monthly deposit.
Monthly contribution required for the future-value gap at the entered return
Defaults:
- future goal: $80,000
- already saved: $8,000
- years until needed: 14
- estimated annual return: 5%
Months: 14 × 12 = 168
Future value of the $8,000 already saved: $16,086.61
Gap the new deposits must cover: 80000 − 16086.61 = $63,913.39
Monthly contribution: $263.45
Total new contributions: 263.45 × 168 = $44,260.20
Calculator result
Child savings goal
- Future goal
- $80,000.00
- Already saved
- $8,000.00
- Years until needed
- 14 years
- Estimated annual return
- 5%
$263.45
monthly contribution
- Current savings future value
- $16,086.61
- Total new contributions
- $44,260.20
- Goal
- $80,000.00
Same goal at 0%: the $8,000 does not grow. Monthly contribution: (80000 − 8000) ÷ 168 = $428.57. The 5% assumption cut the monthly deposit by $165.12. That only works if the 5% shows up for 168 months. The calculator note says this is a planning estimate, not investment advice.
A down payment is the same shape with a shorter clock. The home purchase cash to close defaults need $96,100.00 before move-in. Start at $0, add $900 a month, 3.5%: 7 years 10 months, final balance $97,171.98. If that date is past the year you want to buy, the monthly number has to rise. The return will not close a seven-year gap by itself.
Pick the leftover month first
The monthly deposit has to come from a real month. The monthly budget planner leftover on its defaults is $900.00. That is the ceiling I would type before I promise $800 toward a $25,000 goal and still fund an emergency pile.
If income is lumpy, use the low month. The CFPB emergency-fund guide says a consistent amount beats a heroic one you skip.
Open the savings goal timeline calculator with the cash you have, the target, and a monthly amount you can repeat. Run 0% next to the typed return. If the date is fixed and the cost is known, use the sinking fund contribution calculator. If the year is fixed and the pile is large, the child savings goal calculator solves for the deposit instead of the date.