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Last updated April 11, 2026

Compound Interest Calculator

See what compound interest really does to your money. Toggle between the cost of debt and the growth of savings. Same math, two very different outcomes.

Currency region: Amounts in CAD
Extra monthly payment applied toward this balance.
Compound interest works against you on debt

Unburden helps you fight back.

This calculator gives you a number. The Unburden app gives you a plan to change it. Track your real balances, watch your daily cost drop, and stay motivated.

Generic calculationThis uses a standard formula. It does not account for your specific card terms, grace periods, or promotional rates.
Does not track real balancesYour balance changes every time you make a payment or a charge. This calculator cannot keep up with that.
No payoff strategyKnowing interest cost is step one. Choosing Snowball, Avalanche, or Momentum to pay it off is where progress happens.
No daily cost trackingYou see a total. The Unburden app shows you the daily cost of your debt and updates it in real time as you pay down.
Feature This Calculator Unburden App
Compound interest calculation
Year-by-year breakdown
Daily interest cost
Track real balances over time
Daily Cost Counter (live updates)
Snowball / Avalanche / Momentum
Burden Score (0-100)
Debt-free date projection
What-if scenarios
Payment reminders
Milestone share cards
100% device-local dataN/A

Your debt has a daily price tag.

Unburden's Daily Cost Counter shows you exactly what your debt costs you every single day. Watch it drop as you pay down. That number updates in real time as your balances change. It is one of the most motivating features in the app.

Stop paying interest. Start tracking your payoff.

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Free includes Burden Score, 3 debts, Snowball + Avalanche. No credit card required.

How compound interest works: for you and against you

Compound interest is interest calculated on both your principal and the interest that has already accumulated. When you are saving, it is the engine that turns small, consistent deposits into large sums over decades. When you are carrying debt, it is the mechanism that makes your balance grow even when you are not spending.

The formula is the same in both cases. The only difference is which side of the equation you are on. This calculator lets you see both sides so you understand what compound interest is doing to your money right now.

Compound interest on debt

Most credit cards compound interest daily. Your annual rate is divided by 365, and that daily rate is applied to your outstanding balance each day. That means interest is being charged on yesterday's interest.

This is why minimum payments are a trap. A $20,000 balance at 22.99% APR with a $400 minimum payment will take over 9 years to pay off. You will pay more than $15,000 in interest alone. The balance is barely moving because most of your payment is going toward interest, not principal.

The longer you carry the balance, the more compound interest costs you. Every month you delay an extra payment is another month the compounding machine works against you.

Compound interest on savings

The same math that punishes you on debt rewards you when you save. A high-yield savings account at 4.5% compounded monthly turns $10,000 into $12,508 in five years without adding a dollar. Add $200 a month and you are looking at $25,904.

The takeaway: every dollar freed from high-interest debt is a dollar that can start compounding in your favor instead of against you. That is why paying off high-interest debt is considered one of the highest-return financial moves you can make.

Unburden helps you free those dollars. Pick a payoff strategy, track your progress, and watch your Burden Score drop as your debt shrinks. Free to start, and your data never leaves your device.

The daily cost of debt

Here is a reframe that makes compound interest tangible. Take your balance, multiply it by your APR, and divide by 365. That is what your debt costs you per day in interest.

A $20,000 balance at 22% APR costs $12.05 per day. Every single day you carry that balance, $12.05 disappears into interest charges before you buy anything. That is $361 per month, $4,380 per year, going toward nothing you can see or use.

When you frame debt in daily terms, the urgency becomes real. A $500 extra payment does not sound like much until you realize it drops your daily cost by about $0.30 permanently. Stack enough of those payments and the daily cost collapses.

Unburden's Daily Cost Counter shows your exact daily interest cost and updates it as you pay down. Watching that number shrink is one of the most motivating parts of the payoff journey. See yours free in the app.

Rule of 72

The Rule of 72 is a quick way to estimate how long it takes money to double at a given interest rate. Divide 72 by the annual rate. At 8% growth, your savings double in roughly 9 years. At 24% on a credit card, your debt doubles in about 3 years if you make no payments.

This shortcut is useful for gut-checking whether your money is working for you or against you. If your savings are earning 4% and your debt is charging 22%, you know which side of the equation needs attention first.

What is the Burden Score?

Your credit score measures your value to lenders. The Burden Score measures your risk to yourself. It is a 0-100 score built on five proprietary stress signals that capture how much pressure your debt is actually putting on your life. A 780 credit score and a Critical Burden Score can exist on the same person.

This calculator can tell you what compound interest will cost you. The Burden Score tells you how vulnerable you are right now. You can find yours free in the Unburden app in about 60 seconds.

Common questions

What is compound interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. On savings, it means your money grows faster over time because you earn interest on your interest. On debt, it means you owe more because interest charges generate their own interest charges. It is the single most important concept in personal finance.
How does credit card interest compound?
Most credit cards compound interest daily. Your annual rate is divided by 365 to get a daily periodic rate, and that rate is applied to your balance each day. This means interest is charged on yesterday's interest, which is why a 22% APR actually costs you closer to 24.6% per year when you account for daily compounding. This calculator lets you toggle to daily compounding to see the real cost.
What is the Rule of 72?
The Rule of 72 is a quick mental math shortcut for estimating how long it takes money to double at a given interest rate. Divide 72 by the annual rate. At 6% interest, money doubles in roughly 12 years. At 24% interest on debt, the amount you owe doubles in about 3 years. It works in both directions and is accurate enough for quick estimates.
Is compound interest good or bad?
Compound interest is neither inherently good nor bad. It depends on which side you are on. When you are saving or investing, compound interest works for you by growing your money faster over time. When you carry debt, compound interest works against you by making your balance grow even when you are not spending. The goal is to get compound interest working in your favor, not against you.
What is the Burden Score?
The Burden Score is a 0-100 financial vulnerability score available free in the Unburden app. Your credit score measures your value to lenders. Your Burden Score measures your risk to yourself. It captures how much pressure your debt is putting on your life across five proprietary stress signals. A 780 credit score and a Critical Burden Score can exist on the same person.

Disclaimer: Unburden is a planning tool, not a financial advisor. The calculations above are estimates based on the information you provide and assume a fixed interest rate with consistent compounding. Actual results will vary based on individual circumstances, rate changes, fees, grace periods, and payment behavior. The Burden Score is an educational estimate, not financial advice. If you are struggling with debt, consider speaking with a Licensed Insolvency Trustee.

Compound interest is costing you daily. Track your real cost and start your payoff plan.

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