Traditional IRA Calculator Formula
Understand the math behind the traditional ira calculator. Each variable explained with a worked example.
Formulas Used
Pre-Tax Value
pre_tax_value = monthly_rate > 0 ? current_balance * pow(1 + monthly_rate, num_months) + monthly_contrib * (pow(1 + monthly_rate, num_months) - 1) / monthly_rate : current_balance + monthly_contrib * num_monthsAfter-Tax Value
after_tax_value = (monthly_rate > 0 ? current_balance * pow(1 + monthly_rate, num_months) + monthly_contrib * (pow(1 + monthly_rate, num_months) - 1) / monthly_rate : current_balance + monthly_contrib * num_months) * (1 - retirement_tax_rate / 100)Annual Tax Savings Now
tax_savings_now = annual_contribution * retirement_tax_rate / 100Variables
| Variable | Description | Default |
|---|---|---|
current_balance | Current Balance(USD) | 20000 |
annual_contribution | Annual Contribution(USD) | 7000 |
annual_return | Expected Return(%) | 7 |
years | Years to Retirement(years) | 25 |
retirement_tax_rate | Expected Retirement Tax Rate(%) | 22 |
monthly_rate | Derived value= annual_return / 12 / 100 | calculated |
monthly_contrib | Derived value= annual_contribution / 12 | calculated |
num_months | Derived value= years * 12 | calculated |
How It Works
Traditional IRA
Contributions may be tax-deductible, reducing your current taxable income. Growth is tax-deferred, but withdrawals are taxed as ordinary income.
After-Tax Retirement Value
After-Tax = Pre-Tax Value x (1 - Retirement Tax Rate)
Traditional IRAs require minimum distributions (RMDs) starting at age 73.
Worked Example
$20,000 balance, $7,000/year, 7% return, 25 years, 22% retirement tax.
current_balance = 20000annual_contribution = 7000annual_return = 7years = 25retirement_tax_rate = 22
- 01Pre-tax value = ~$618,000
- 02After-tax = $618,000 x (1 - 0.22) = ~$482,000
- 03Annual tax savings now = $7,000 x 0.22 = $1,540
Ready to run the numbers?
Open Traditional IRA Calculator