Learn · Topic hub
Investing & wealth building
Investing calculators on this site illustrate math: compound returns, contribution schedules, and rental cash flow—not portfolio recommendations or tax advice.
Real returns depend on fees, taxes, timing of deposits, and whether returns are reinvested. Use conservative rates when stress-testing a plan.
Compound growth and regular deposits
Compound interest means earnings in one period become part of the balance that earns in the next. Regular deposits add more than the headline rate suggests because each deposit has its own timeline.
Small differences in assumed annual return change long horizons dramatically. Compare a base case, a lower return, and a higher return instead of trusting a single optimistic percent.
Retirement savings illustrations
Retirement projections combine what you already saved, ongoing contributions, and an assumed return until a target age. They ignore market crashes, job changes, and tax treatment unless you model them separately.
401(k) and Roth IRA tools on this site show account growth mechanics. They do not know your employer match rules, income limits, or required distributions.
Rental property cash flow
Cash flow is rent minus operating expenses and debt service, before taxes. Cap rate and cash-on-cash return use different denominators (property value vs cash invested).
Vacancy, maintenance, capex reserves, and property management fees vary by market. Stress-test with higher vacancy and lower rent growth than your best-case pro forma.
Inflation and purchasing power
Inflation reduces what a dollar buys over time. Year-over-year CPI is a broad index; your personal inflation depends on what you spend on (housing, childcare, healthcare).
Nominal account balances can rise while purchasing power falls if returns barely beat inflation. Compare “today’s dollars” when a calculator offers that view.
Common questions
Are these projections guaranteed returns?
No. You enter the rate, volatility is not modeled, and past market performance is not a promise of future results.
Should I use pre-tax or Roth accounts?
That depends on current vs expected future tax rates, liquidity needs, and employer match. These calculators show account growth; they do not optimize tax strategy.
What discount rate makes sense for rental property?
Investors often use a required return that reflects risk, financing cost, and illiquidity. Compare the property to other uses of the same down payment, not to a stock index alone.
Guides on this topic
- How rental cash flow is estimatedFollow rent, vacancy, expenses, and loan payment from inputs to monthly cash flow and cap rate.
- How compound interest is estimatedLearn how compounding frequency and contributions build the projected balance in the compound interest calculator.
- How retirement savings are projectedSee how monthly saving, growth, and optional withdrawals project a balance to retirement age.
Related calculators
These tools use the inputs you provide. They are illustrations, not offers or advice. Browse the full directory with category filters on the calculators page.
- Investment propertyEstimate rent, expenses, and loan cost for a rental.Open
- Compound interestProject growth of a balance over time.Open
- RetirementProject savings toward a retirement goal.Open
- 401(k) CalculatorProject a 401(k) balance at retirement from contributions, employer match, and a return you enter.Open
- Roth IRA CalculatorProject a Roth IRA balance at retirement and compare a simplified Roth vs traditional illustration.Open
- FIREEstimate a financial-independence number from spending and a withdrawal rate you choose.Open
- Net worthAdd up assets and debts, then project the balance you enter.Open