When you pay off a purchase in monthly instalments, you pay the price plus interest.
But there's a third number nobody shows you. The money that could have been growing while those payments went to the bank instead.
Free Opportunity Cost Calculator
Find out the real price of every purchase you put on credit. Not just the interest. The future money you gave up too.
Use the free calculatorFor educational purposes only. Not financial advice.
The true cost
When you pay off a purchase in monthly instalments, you pay the price plus interest.
But there's a third number nobody shows you. The money that could have been growing while those payments went to the bank instead.
Purchase price, interest, and opportunity cost.
Most calculators show you one. This one shows all three.
The average annual return money earns when invested in shares over the long term.
That's the benchmark your monthly payments are losing against.
The TRUE COST. What a purchase costs you.
Purchase price, plus interest, plus what that money could have become.
This tool is for educational purposes only. It is not financial advice. The 7% figure is a general historical reference, not a guarantee of future returns.
What it does
Enter a purchase amount, your card's interest rate, and what you can pay each month.
The calculator does the rest.
Use the free calculator
A simple educational tool to help you see what a credit card purchase can really cost
once interest and lost opportunity are included. Try a dinner, a phone, a weekend away,
or any purchase you're tempted to put on credit.
No payment. No subscription. No jargon. Just clearer money maths.
The dinner is gone. The debt is not.
Your result is ready. Enter your email to reveal it, free.
This tool is for educational purposes only and is not financial advice. The figures are illustrative and based on the assumptions you enter. The 7% growth figure is a general long-term reference only and is not a guarantee of future returns.
Put it to work
Run the numbers before you reach for the card. The purchase might still make complete sense. Or the true cost might change the conversation. Either way, you'll know what you're agreeing to, not just the sticker price.
"No interest for 12 months" still has a catch, usually a high rate that kicks in the moment you miss the deadline. Enter the full amount, the revert rate, and what you can realistically pay each month. See the actual number before you sign up.
Try increasing the monthly payment slider by $50 or $100. The months that disappear, and the interest and opportunity cost that goes with them, are almost always more than people expect. Sometimes a small change makes a surprisingly large difference.
You've been thinking about it for weeks. That's okay. This isn't about saying no. It's about seeing the full number before you say yes. The calculator doesn't make the decision for you. It just makes sure you're deciding with clear eyes.
A $600 phone versus a $1,200 one. Both on credit. Both paid off at $50 a month. The gap between their true costs is rarely what the price tags suggest. Run both scenarios, see the real difference, then choose the one that makes sense for you.