Monthly Savings Calculator
How much will regular monthly contributions grow over time — and how much do you need to save each month to hit your goal?
Quick Reference at 5% APY
$200/mo × 20yr: $82,207$500/mo × 20yr: $205,517$500/mo × 30yr: $416,129$1,000/mo × 20yr: $411,034Need $100k in 20yr: $243.29/moNeed $100k in 10yr: $643.99/mo
Future Value of Monthly Contributions
Over:
| Monthly | 3% | 4% | 5% | 6% | 7% | 8% |
|---|---|---|---|---|---|---|
| $100/mo | $32,830 $8,830 interest | $36,677 $12,677 interest | $41,103 $17,103 interest | $46,204 $22,204 interest | $52,093 $28,093 interest | $58,902 $34,902 interest |
| $200/mo | $65,660 $17,660 interest | $73,355 $25,355 interest | $82,207 $34,207 interest | $92,408 $44,408 interest | $104,185 $56,185 interest | $117,804 $69,804 interest |
| $300/mo | $98,491 $26,491 interest | $110,032 $38,032 interest | $123,310 $51,310 interest | $138,612 $66,612 interest | $156,278 $84,278 interest | $176,706 $104,706 interest |
| $500/mo | $164,151 $44,151 interest | $183,387 $63,387 interest | $205,517 $85,517 interest | $231,020 $111,020 interest | $260,463 $140,463 interest | $294,510 $174,510 interest |
| $750/mo | $246,226 $66,226 interest | $275,081 $95,081 interest | $308,275 $128,275 interest | $346,531 $166,531 interest | $390,695 $210,695 interest | $441,765 $261,765 interest |
| $1,000/mo | $328,302 $88,302 interest | $366,775 $126,775 interest | $411,034 $171,034 interest | $462,041 $222,041 interest | $520,927 $280,927 interest | $589,020 $349,020 interest |
| $1,500/mo | $492,453 $132,453 interest | $550,162 $190,162 interest | $616,551 $256,551 interest | $693,061 $333,061 interest | $781,390 $421,390 interest | $883,531 $523,531 interest |
| $2,000/mo | $656,604 $176,604 interest | $733,549 $253,549 interest | $822,067 $342,067 interest | $924,082 $444,082 interest | $1,041,853 $561,853 interest | $1,178,041 $698,041 interest |
* Contributions made at end of each month, compounded monthly, no initial deposit. Term: 20 years.
How Much to Save Monthly to Reach Your Goal
Required monthly contribution at 5% APY to reach these savings targets:
| Goal Amount | In 10 years | In 15 years | In 20 years | In 25 years | In 30 years |
|---|---|---|---|---|---|
| $50,000 | $321.99/mo | $187.06/mo | $121.64/mo | $83.96/mo | $60.08/mo |
| $100,000 | $643.99/mo | $374.13/mo | $243.29/mo | $167.92/mo | $120.15/mo |
| $250,000 | $1,609.97/mo | $935.32/mo | $608.22/mo | $419.81/mo | $300.39/mo |
| $500,000 | $3,219.94/mo | $1,870.63/mo | $1,216.45/mo | $839.62/mo | $600.77/mo |
| $1,000,000 | $6,439.88/mo | $3,741.27/mo | $2,432.89/mo | $1,679.23/mo | $1,201.55/mo |
* At 5% APY, monthly compounding, no initial deposit.
What Does an Extra $100/Month Actually Do?
The compounded impact of adding just $100 more per month at 5% APY:
After 10 years
$15,528
deposited: $12,000
interest: $3,528
After 15 years
$26,729
deposited: $18,000
interest: $8,729
After 20 years
$41,103
deposited: $24,000
interest: $17,103
After 30 years
$83,226
deposited: $36,000
interest: $47,226
Monthly Contributions vs Lump Sum — Side by Side
Compare investing $500/month vs. dropping a $60,000 lump sum (same total after 10 years) at 5% APY:
$500/mo for 10 years
$77,641
Total deposited: $60,000
Interest earned: $17,641
$60,000 lump sum invested now
$98,821
Total deposited: $60,000
Interest earned: $38,821
The lump sum wins because all $60,000 compounds from day one. Monthly contributions start with less, so less compounds early. But most people don't have $60,000 sitting idle — so monthly contributions are the practical path.
Calculate Your Monthly Savings Growth
Frequently Asked Questions
At 5% APY: $205,516. At 7%: $262,481. At 4%: $183,724. You contribute $120,000 total over 20 years — so at 5%, compound interest adds $85,516 on top of your deposits. The longer the time horizon, the more dramatic the gap between deposits made and interest earned.