Retirement Savings Calculator
Projected retirement balance from current savings plus a monthly contribution
Interactive Sandbox
Adjust values in real-time and observe mathematical cause-and-effect
Exponential Compounding Growth: Returns generate subsequent returns over time t, rapidly accelerating capital growth.
Variable Mechanics
Roles, constraints & impacts
Current Savings
Formula Parameter
Monthly Contribution
Formula Parameter
Expected Annual Return
Formula Parameter
Years Until Retirement
Formula Parameter
At a Glance
Gotchas, units & real-world use
Formula Nature & Mechanics
Exponential Compounding Growth: Returns generate subsequent returns over time t, rapidly accelerating capital growth.
Common Mistakes & Traps
- Entering annual percentage rate (e.g. 7%) as 7 instead of converting to decimal 0.07.
- Neglecting the compounding frequency (n): monthly compounding produces higher yield than annual.
- Ignoring inflation drag when evaluating long-term nominal returns.
Dimensional Analysis & Units
Currency × (1 + rate)^time = Future Currency ($)
Real-World & Industry Application
Retirement 401(k) / Roth IRA compounding, mortgage amortization schedules, bond yield analysis, and inflation depreciation modeling.
Worked Example: Retirement Savings
Given:
- current = 50000
- monthly = 500
- rate = 7
- years = 25
- Current savings grow to $50,000 × (1 + 0.5833%)^300 = $286,270.91
- Monthly contributions grow to $500 × ((1 + i)ⁿ − 1) ÷ i = $405,035.85
- Retirement balance = $691,306.76
- You put in $200,000; growth adds $491,306.76
- At a 4% withdrawal rate this supports about $2,304.36 per month
Answer: 691306.76
Frequently Asked Questions
What is the Retirement Savings formula?
FV = S(1 + i)ⁿ + P × ((1 + i)ⁿ − 1) ÷ i. Projected retirement balance from current savings plus a monthly contribution.
How do I calculate Retirement Savings?
Enter Current Savings (current), Monthly Contribution (monthly), Expected Annual Return (rate), Years Until Retirement (years) into the calculator. It applies FV = S(1 + i)ⁿ + P × ((1 + i)ⁿ − 1) ÷ i and shows every step of the working.
