Investment Calculator — Calculadora Online Grátis
Investment growth with inflation adjustment, contribution step-up, tax on gains and real vs nominal return comparison
Sobre Esta Calculadora
This investment calculator goes beyond basic compound growth to model the four factors that determine what your portfolio is actually worth in purchasing power: nominal return, inflation erosion, tax drag on gains, and contribution growth over time.
Real vs. nominal return: a 7% nominal return with 3% inflation yields only a 3.88% real return (not 4% — inflation compounds too). On $100,000 over 20 years, the difference between what your account statement says ($386,968) and what that money actually buys in today's dollars ($234,965) is $151,000 — more than your original investment.
Tax drag depends on whether the account is taxable, tax-deferred (traditional IRA/401k), or tax-free (Roth). In a taxable account, annual dividends and capital gains distributions are taxed each year, reducing the compounding base. A 20% tax on annual returns turns a 7% nominal return into an effective 5.6% — eliminating $82,000 over 20 years on $100,000.
Contribution step-up of 5%/year reflects the realistic pattern of rising income. A 35-year-old starting with $10,000 and contributing $500/month with a 5% annual step-up reaches $1.47M by 65 vs. $1.06M with flat contributions — a $410,000 difference from a behaviorally realistic assumption.
Use this calculator to set a concrete investment target and work backwards to the monthly contribution you need today.
Fórmula
Real Return = [(1 + Nominal Rate) / (1 + Inflation Rate)] - 1 FV = PV × (1+r)^n + PMT × [(1+r)^n - 1] / r
Exemplo Resolvido
Real vs nominal growth: $50,000 invested for 20 years at 8% with 3% inflation and 15% tax on gains
Entradas:
- Starting investment: $50,000
- Annual contribution: $6,000 (growing 3%/year)
- Nominal return: 8%
- Inflation rate: 3%
- Tax rate on annual gains: 15%
Passo a Passo:
- Nominal FV (no tax, no inflation): $50,000 × 1.08^20 + contributions FV ≈ $558,000
- After-tax return: 8% × (1 − 0.15) = 6.8% effective annual return
- After-tax FV: ≈ $474,000
- Real return: (1.068) / (1.03) − 1 = 3.69% real after-tax return
- Real purchasing power: $474,000 / 1.03^20 = $262,600 in today's dollars
Dicas
- Inflation erodes purchasing power — a 7% return with 3% inflation is only a 3.88% real return.
- Annual contribution step-up of just 5% per year can nearly double your retirement corpus compared to flat contributions.