Quick Answer
Reaching a $50,000 savings goal from $5,000 with $500 monthly contributions at 5% annual interest takes an estimated 73 months (approximately 6 years and 1 month), with estimated interest of approximately $3,634.
Common Examples
| Input | Result |
|---|---|
| Goal $50,000, current $5,000, $500/month, 5% rate | Estimated 73 months to reach goal |
| Goal $25,000, current $2,000, 4% rate, 36 months | Estimated $622/month contribution needed |
| Goal $100,000, current $10,000, $800/month, 6% rate | Estimated 85 months to reach goal |
| Current $10,000, $300/month, 5% rate, 120 months | Estimated $62,934 final balance |
| Goal $20,000, current $0, $400/month, 4.5% rate | Estimated 46 months to reach goal |
How It Works
This calculator uses the future value formula for a lump sum combined with regular contributions:
FV = PV x (1 + r)^n + PMT x ((1 + r)^n - 1) / r
Where:
- FV = future value (savings goal or final balance)
- PV = present value (current savings)
- PMT = monthly contribution
- r = monthly interest rate (annual rate / 12 / 100)
- n = number of months
The formula can be rearranged to solve for any one unknown:
- Solve for months (n): iterative simulation month by month until the balance reaches the goal
- Solve for PMT: PMT = (FV - PV x (1+r)^n) / (((1+r)^n - 1) / r)
- Solve for FV: direct calculation using the formula above
Worked Example
To reach a $50,000 goal starting from $5,000 with $500 monthly contributions at 5% annual interest:
Monthly rate r = 0.05 / 12 = 0.004167. Month 1: Balance = $5,000 x 1.004167 + $500 = $5,520.83. Month 2: $5,520.83 x 1.004167 + $500 = $6,043.83. This continues month by month. After 73 months, the balance reaches approximately $50,000. Total contributions = $5,000 + ($500 x 73) = $41,500. Estimated interest earned = approximately $8,500.
To solve for monthly contribution: if the goal is $25,000, current savings are $2,000, and the time frame is 36 months at 4%, r = 0.003333. FV of current savings = $2,000 x (1.003333)^36 = $2,254.54. Remaining needed = $25,000 - $2,254.54 = $22,745.46. Annuity factor = ((1.003333)^36 - 1) / 0.003333 = 37.62. Monthly contribution = $22,745.46 / 37.62 = approximately $604.70.
Related Calculators
Frequently Asked Questions
What interest rate should I use for a savings account?
Does this account for taxes on interest?
How accurate is the time estimate?
Can I use this for retirement savings planning?
What if I already have enough saved?
Learn More
Complete Guide to Compound Interest
How compound interest works, the math behind it, and how compounding frequency, time, and rate affect your money. Includes worked examples and common scenarios.
How to build an emergency fund
Learn how to calculate your emergency fund target, where to keep it, and how to build it month by month with a concrete savings plan.
CalculateY