Interactive calculators

Money tools

Plug in your own numbers to see how everyday money decisions play out. Everything runs in your browser — nothing you type is saved or sent anywhere.

50/30/20 budget planner

Split take-home pay into needs, wants, and savings and see how your plan compares.

Lesson: Budgeting →
Needs
$1,100
Wants
$500
Savings
$300
Needs55% (goal ≤50%)
Wants25% (goal ≤30%)
Savings15% (goal ≥20%)
Unassigned$100.00

Give the remaining $100.00 a job: savings, a goal, or a buffer. The markers show the 50/30/20 guideline.

Savings goal timer

Find out how long it takes to reach a goal and what to save each week.

Lesson: Saving →
Check current rates at your bank or credit union.
Time to goal1 year
Without interest1 year
To finish in 6 months$150.00/mo
To finish in 12 months$75.00/mo · $17.31/wk

Interest is estimated with monthly compounding of the APY. Actual rates can change.

Compound interest explorer

Watch a balance grow year by year with deposits and compounding.

Lesson: Interest & compound interest →
Money you put inInterest earned
Ending balance$26,412.25
You deposited$13,000.00
Interest earned$13,412.25
$1,000 alone at simple interest$2,200.00

Rule of 72: at 6% money roughly doubles every 12.0 years. Illustration only: assumes a constant rate, no fees or taxes, and deposits at the end of each month. Returns are not guaranteed.

Credit utilization checker

Calculate how much of your available credit you are using.

Lesson: Credit scores & reports →
Utilization26.0%
StatusUnder 30% — generally healthy
Total balance$650
Balance for under 30%$750

Utilization is one factor in many credit scoring models; payment history also matters a lot. Paying in full each month avoids interest.

Debt payoff calculator

See how payment size changes payoff time and total interest.

Lesson: Debt & borrowing →

Paying $60.00/mo

Payoff time4 years, 8 months
Total interest$1,328.83

Paying $100.00/mo

Payoff time2 years, 2 months
Total interest$579.75

Paying $40.00 more each month saves about $749.09 in interest and finishes 30 months sooner.

Assumes a fixed APR, no new charges, and no fees. Credit card minimum payments often change as the balance falls.

Start-early investing comparison

Compare the same monthly investment started at two different ages.

Lesson: Investing fundamentals →
Start at 18
$438,643
Start at 28
$209,654
Start at 18: deposited$56,400
Start at 28: deposited$44,400
Difference at the end$228,988
Extra deposits by early starter$12,000

Hypothetical constant return for illustration only. Real investments rise and fall, can lose value, and have fees. This is not investment advice.

Paycheck estimator

Estimate gross pay, FICA, withholding, and take-home pay.

Lesson: Taxes & paychecks →
Some states have no income tax.
Sample pay statement (per paycheck)
Gross pay$600.00
Social Security + Medicare (FICA 7.65%)−$45.90
Federal income tax withholding−$30.00
State income tax withholding−$18.00
Net (take-home) pay$506.10
Yearly gross$15,600
Yearly take-home$13,159
Take-home share84%

Simplified estimate. Actual withholding depends on your W-4, filing status, and current tax rules; many teens with low income owe little or no federal income tax and may get withholding back by filing. See irs.gov.

Opportunity cost calculator

See what a regular purchase could grow to if saved instead.

Lesson: Financial decision-making →
e.g. a drink, snack, or app purchase
Per year$936
Spent over 10 years$9,360
If saved and earning interest$12,112

This doesn't mean you should never treat yourself — it shows the tradeoff so the choice is intentional.

Education cost comparison

Compare two programs by net price and estimated loan payments.

Lesson: College & career finance →
Total net price$60,000
Est. loan payment (10 yrs)$227.10/mo
Interest over repayment$7,252
Total net price$10,000
Est. loan payment (10 yrs)$56.77/mo
Interest over repayment$1,813

Use each school's Net Price Calculator and current federal loan rates at studentaid.gov. A common guideline is to keep total student loans below your expected first-year salary.

Insurance plan comparison

Compare total yearly cost of two plans at different usage levels.

Lesson: Insurance & risk →
Total yearly cost (premiums + your share)
ScenarioLow deductibleHigh deductible
Low use ($300)$2,460$1,440 ✓
Your estimate ($1,500)$2,860$2,640 ✓
Major event ($20,000)$5,160 ✓$7,140

Simplified model: ignores copays, networks, and exclusions. Real policies differ, so read the plan's Summary of Benefits and Coverage.