Compound Interest Calculator

Calculate how your investments grow over time with the power of compounding.

Your numbers
Initial Investment
$
Monthly Contribution
$
Annual Return
%
Years
yrs
Final Portfolio Value
After 30 years
×1x
Total Invested
Principal
Interest Earned
Pure growth
Return Ratio
Interest / Total
Monthly Growth
Final year avg
Investment growth over time
Total value
Amount invested

How compound interest works

Compound interest is one of the most powerful forces in personal finance...

The formula is straightforward: A = P(1 + r/n)^(nt)...

The power of time

An investor who puts $5,000/year...

What return rate to expect

The S&P 500 has historically returned...

Why monthly contributions matter

Your monthly contribution is often more impactful...

Compound interest vs. simple interest

Simple interest pays a fixed percentage...

Frequently asked questions

Compound interest is interest calculated on both the initial principal and accumulated interest.

More frequent compounding yields slightly more.

S&P 500 has historically returned ~10% annually.

$10,000 plus $500/month at 7% for 30 years grows to ~$567,000.

Divide 72 by your annual return rate to estimate doubling time.

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Retirement Calculator

Plan when you can retire and whether your savings will cover your lifestyle.

Your profile
Current Age
yrs
Retirement Age
yrs
Current Savings
$
Monthly Contribution
$
Annual Return
%
Monthly Spend in Retirement
$
Retirement Portfolio
At retirement
✓ On Track
✓ Your plan looks sustainable.
Monthly Income
4% rule
Coverage
Income vs spend
Required Capital
25× annual spend
Portfolio Lasts
Years in retirement
Portfolio growth to retirement
Portfolio
Required capital

How to plan for retirement

Retirement planning is the process...

A commonly accepted framework is the 25x rule...

The 4% withdrawal rule

Based on the Trinity Study...

How much should I save each month?

A common guideline is 10–15%...

What if my retirement plan shows a shortfall?

You have several levers...

Frequently asked questions

Use the 25x rule.

Withdraw 4% in year one then adjust for inflation.

Yes. Subtract expected benefits from monthly spending target.

This uses nominal returns. Subtract 2–3% for inflation-adjusted planning.

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FIRE Calculator

Calculate your FIRE number and how many years until financial independence.

Your FIRE profile
Current Age
yrs
Monthly Expenses
$
Current Savings
$
Monthly Investment
$
Annual Return
%
FIRE Number
Capital needed for financial independence
Age —
Years to FIRE
From today
Monthly Passive
At FIRE (4% rule)
Progress to FIRE
0%
Path to financial independence
Portfolio
FIRE target

What is the FIRE movement?

FIRE stands for Financial Independence, Retire Early...

Once your portfolio generates enough...

How to calculate your FIRE number

FIRE number = Annual Expenses × 25...

Types of FIRE

Lean FIRE, Fat FIRE, Barista FIRE, Coast FIRE...

Savings rate is the key variable

At 10% savings rate you need ~43 years...

Frequently asked questions

Annual expenses × 25.

Many use 3–3.5% for longer horizons.

When you've invested enough to compound to FIRE without more contributions.

To reach $1M in 15 years at 7%, about $3,350/month from $0.

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Savings Goal Calculator

Calculate exactly how much to save each month to reach any financial goal on time.

Your goal
Financial Goal
$
Current Savings
$
Time to Reach Goal
yrs
Annual Return
%
Monthly Savings Needed
To reach your goal on time
Reachable
Total Contributed
Your savings
Interest Earned
Free money
Daily Target
Per day
Weekly Target
Per week
Projected savings growth
Projected
Target

How to set and reach a savings goal

A savings goal is a specific financial target...

Make your goal SMART...

Where to keep your savings

Under 2 years: HYSA...

The automation advantage

Automating your savings on payday...

The 50/30/20 budgeting rule

50% needs, 30% wants, 20% savings...

Frequently asked questions

3–6 months of essential expenses.

For 1–3 year horizon, use HYSA or short-term CDs.

Uses the future value annuity formula.

The calculator will show $0 monthly needed.

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Inflation Calculator

See how inflation erodes purchasing power over time.

Your numbers
Current Amount
$
Annual Inflation Rate
%
Years Ahead
yrs
Future Equivalent Value
Purchasing power in 20 years
−%
Today's Value
Starting amount
Purchasing Power Lost
Erosion
Needed to Match
Future dollars required
Real Value
% of original
Purchasing power over time
Real value
Original

How inflation erodes your purchasing power

Inflation is the rate at which prices rise...

The U.S. Federal Reserve targets 2%...

Inflation vs. investment returns

A 7% nominal return only nets ~4% real...

What causes inflation?

Demand exceeding supply, rising costs...

How to protect against inflation

Best hedges: equities, real estate, TIPS...

Frequently asked questions

The Fed targets 2%. Historical US average ~3%.

At 3%, $1M purchasing power halves in ~24 years.

Real Return ≈ Nominal Return − Inflation Rate.

Future Value = Present Value ÷ (1 + inflation)^years.

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Investment Return Calculator

Calculate your total return, annualized ROI, and real gain on any investment.

Your investment
Initial Investment
$
Final Value
$
Investment Period
yrs
Inflation Rate
%
Total Return
Net gain on investment
ROI —
Total ROI
Nominal return %
Annualized (CAGR)
Per year
Real Return
After inflation
Net Gain
Dollars earned
Investment growth path
Investment value
Inflation-adjusted

How to calculate investment return

The two most important metrics are Total ROI and CAGR...

CAGR = (Final Value / Initial Value)^(1/Years) − 1...

Nominal vs. real return

At 3% inflation, 10% nominal = 6.8% real...

What is a good CAGR?

S&P 500 historically ~10% nominal CAGR...

The power of CAGR compounding

$10,000 at 8% CAGR for 30 years = $100,000...

Frequently asked questions

Compound Annual Growth Rate — the best metric for comparing investments.

ROI is total percentage gain; CAGR is the annualized rate.

S&P 500: ~10% nominally, ~7% after inflation.

A 1% fee on $100k at 8% for 30 years costs ~$170,000 in lost growth.

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Passive Income Calculator

Find out how much capital you need to generate your target monthly passive income.

Your income target
Target Monthly Income
$
Annual Return / Yield
%
Current Portfolio
$
Monthly Contribution
$
Capital Required
To generate target income
— yrs away
Current Passive Income
Monthly, today
Income Gap
Still needed
Capital Gap
To invest
Progress
Of target
Portfolio growth to passive income goal
Portfolio
Capital needed

How to build passive income from investments

Passive income from investments means earning money without actively working...

To generate $3,000/month at 5% yield, you need $720,000...

Sources of investment passive income

Dividends, bonds, REITs, HYSA...

Total return vs. income approach

A total return strategy often outperforms...

The passive income snowball

Reinvesting income accelerates your journey...

Frequently asked questions

Using 4% rule: multiply annual expenses by 25.

Conservative: 3–4%. Moderate: 4–6%. Aggressive: 6–10%.

Total-return index funds typically outperform dividend-focused strategies.

At 5% yield you need $1.2M. From $0 at $1,500/month, about 25 years.

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Net Worth Calculator

Calculate your net worth and track your financial health.

Your assets & liabilities
Cash & Savings
$
Investments & Retirement
$
Real Estate Value
$
Other Assets
$
Total Debts & Liabilities
$
Net Worth
Total assets minus total liabilities
Positive
Total Assets
Everything you own
Total Liabilities
Everything you owe
Debt-to-Asset Ratio
Lower is better
Liquid Assets
Cash + investments
Asset breakdown
Assets
Liabilities
Net Worth

What is net worth and why does it matter?

Net worth = Total Assets − Total Liabilities...

The goal is a consistent upward trend...

Average net worth by age

Federal Reserve data: under-35 ~$39k...

What counts as an asset?

Cash, investment accounts, real estate equity...

How to increase your net worth

Increase assets and reduce liabilities...

Frequently asked questions

Not necessarily. Common for young adults with student loans.

Yes, but only the equity portion.

Using 4% rule: investable assets × 25.

Monthly or quarterly is ideal.

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Savings Rate Calculator

Calculate your savings rate and see how it accelerates your path to financial freedom.

Your income & expenses
Monthly Take-Home Income
$
Monthly Expenses
$
Annual Return on Investments
%
Current Savings / Portfolio
$
Your Savings Rate
Of take-home income saved
Monthly Savings
Amount invested
Years to FI
At this rate
FI Number
25× annual expenses
Monthly Expenses
Your lifestyle cost
Portfolio growth at current savings rate
Portfolio
FI target

Why your savings rate is the most powerful financial lever

Your savings rate is the single most important variable...

At 10% savings rate, ~43 years to FI...

How to calculate your savings rate

Savings Rate = (Monthly Savings ÷ Income) × 100...

What is a good savings rate?

Standard: 10–15% of gross income. FIRE: 50–70%...

The double impact of a higher savings rate

Every extra dollar saved grows portfolio and proves you need less...

Frequently asked questions

To retire in under 20 years, typically 40–50%+.

FIRE community uses take-home (net) income.

Increase income or reduce expenses. Automate savings on payday.

Not necessarily. Financial security and autonomy predict happiness more than consumption.

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Cost of Car Ownership Calculator

Estimate the real total cost of owning a car including fuel, insurance, maintenance and depreciation.

Your car details
Car Price
$
Years of Ownership
yrs
Annual Mileage
mi
Fuel Efficiency
mpg
Fuel Price
$/gal
Insurance / Year
$
Maintenance / Year
$
Taxes & Registration / Year
$
Annual Depreciation Rate
%
Total Ownership Cost
Over 5 years
Monthly
Monthly Cost
All-in
Annual Cost
Per year
Fuel Total
Over ownership
Depreciation Loss
Value lost
Cost breakdown over ownership
Fuel
Depreciation
Insurance+Maint.

The real cost of owning a car

Most people focus on the sticker price when buying a car, but the true cost of ownership is much higher. Fuel, insurance, maintenance, taxes, and depreciation can easily double what you paid at the dealership.

A $25,000 car driven for 5 years can cost $40,000–$55,000 in total when all expenses are factored in. This calculator breaks down every cost category so you can make an informed decision.

Depreciation: the hidden cost

A new car loses roughly 15–20% of its value per year. After 5 years, the average car retains only 37% of its original value. This is typically the largest single cost of ownership.

Insurance and maintenance

Average US car insurance runs $1,500–$2,500/year. Maintenance averages $500–$1,200/year for a newer car, rising with age. Budget for both.

Frequently asked questions

According to AAA, the average cost of owning and operating a car in the US is around $10,000–$12,000 per year, depending on vehicle type and mileage.

New cars depreciate about 20% in the first year and 15% per year thereafter on average. Buying a 2–3 year old used car avoids the steepest depreciation curve.

Buy used (2–3 years old), choose a fuel-efficient model, shop for insurance annually, keep up with maintenance to avoid large repairs, and drive fewer miles.

For people driving under 5,000 miles/year in urban areas, rideshare or public transit is often cheaper. Above 10,000–15,000 miles/year, car ownership usually wins on cost per mile.

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Car vs Public Transport Calculator

Compare the yearly cost of owning a car versus using public transportation.

🚗 Car costs / year
Car Purchase Price
$
Years of Use
yrs
Fuel Cost / Month
$
Insurance / Month
$
Maintenance / Month
$
Taxes & Fees / Month
$
🚌 Public transport / month
Monthly Transport Cost
$
You save with public transport
Over full ownership period
Per year
Car Annual Cost
All expenses
Transit Annual Cost
Public transport
Annual Difference
Car minus transit
Total Difference
Over ownership
Annual cost comparison
Car
Public Transport

Car vs public transport: which is cheaper?

In most cities, public transport is significantly cheaper than car ownership when all costs are included — car payments, fuel, insurance, parking, and maintenance. But convenience and time also matter.

A car costing $800/month versus a transit pass at $120/month represents a $8,160 annual difference. Over 7 years, that's $57,000 — enough for a substantial investment portfolio.

Hidden car costs

Parking ($100–$300/month in cities), tolls, and the opportunity cost of capital tied up in a depreciating asset are rarely factored into car comparisons.

When a car makes sense

For suburban or rural residents, families, or jobs requiring a car, ownership is often unavoidable. The goal is to minimize costs through smart choices.

Frequently asked questions

In most urban areas, yes. Public transport typically costs $50–$150/month vs. $700–$1,200/month for a car when all expenses are included.

Include: purchase price (amortized), fuel, insurance, maintenance, taxes and registration, parking, and tolls. Many people underestimate by 30–40%.

Investing the monthly difference at 7% returns can grow substantially. $600/month saved over 10 years = ~$104,000 in an index fund.

Yes — many people use transit for daily commutes and rent a car for occasional trips. Car-sharing services like Zipcar can cost $10–$15/hour for occasional use.

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Car Affordability Calculator

Estimate the maximum car price you can afford based on your income, expenses and financing.

Your finances
Monthly Take-Home Income
$
Monthly Expenses
$
Down Payment / Savings
$
Loan Interest Rate
%
Loan Term
yrs
Max Car Price You Can Afford
Based on 15% of monthly income rule
Affordable
Est. Monthly Payment
Loan only
Total Loan Cost
Principal + interest
Interest Paid
Cost of financing
Max Monthly Budget
15% of income
Loan repayment breakdown
Principal
Interest

How much car can you afford?

A common rule of thumb is to spend no more than 15% of your monthly take-home pay on your total car payment. This includes the loan, insurance, and fuel combined.

For a $5,000/month income, that's $750/month maximum for all car expenses. At 6% interest over 5 years, that supports a loan of around $38,000.

The 20/4/10 rule

Put 20% down, finance for no more than 4 years, and keep total car expenses under 10% of gross income. This is a conservative but financially sound approach.

New vs used car financing

Used car loans typically carry higher interest rates (1–3% more) but lower purchase prices. Calculate total cost of financing, not just monthly payment.

Frequently asked questions

A common guideline is to spend no more than 15–20% of your monthly take-home pay on all car-related expenses, or keep the car price under 50% of your annual salary.

For new cars with good credit (700+), rates of 4–7% are typical. For used cars, expect 6–12%. Shopping multiple lenders and credit unions can save thousands.

Yes — a larger down payment reduces the loan principal, lowers monthly payments, reduces interest paid, and keeps you from being "underwater" on the loan.

Financial experts recommend 48–60 months max. Longer terms lower payments but increase total interest paid and risk of negative equity as the car depreciates.

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Fuel Cost Calculator

Calculate how much fuel will cost for any trip based on distance and fuel efficiency.

Trip details
Distance
mi
Fuel Efficiency
mpg
Fuel Price
$/gal
Trips per Month
×
Cost per Trip
For 300 miles at 30 mpg
Fuel Needed
Gallons per trip
Monthly Fuel Cost
At 2 trips/month
Annual Fuel Cost
Per year
Cost per Mile
Fuel only
Monthly fuel cost at different prices

How to calculate fuel cost for a trip

Fuel cost = (Distance ÷ Fuel Efficiency) × Fuel Price. For a 300-mile trip in a car that gets 30 mpg with fuel at $3.50/gallon: 300÷30 × $3.50 = $35.

Fuel is typically the second-largest car expense after depreciation. Improving fuel efficiency by even 5 mpg can save $200–$400/year depending on mileage.

Tips to improve fuel economy

Keep tires properly inflated, avoid aggressive acceleration, use cruise control on highways, and reduce AC use. These habits can improve efficiency by 10–20%.

Electric vs gas cost comparison

At $0.13/kWh and 3.5 miles/kWh, an EV costs about $0.037/mile vs. $0.12/mile for a 30 mpg gas car at $3.50/gal — about 3× cheaper per mile.

Frequently asked questions

Divide the total distance by your car's fuel efficiency (mpg) to get gallons needed, then multiply by the price per gallon. This calculator does it instantly.

The average US driver spends $150–$250/month on gasoline, depending on vehicle, driving habits, and local fuel prices.

Yes significantly. Most cars are most efficient between 45–65 mph. Driving at 80 mph vs. 65 mph typically uses 15–25% more fuel.

Under-inflated tires can reduce fuel economy by 0.5–3%. At high mileage, this adds up — always keep tires at the manufacturer-recommended PSI.

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