🔗 Debt Consolidation Calculator: Compare One Loan to Many Debts
By Shihab Mia · Updated 2026-07-01
This calculator gives estimates based on the figures you enter and is not professional financial advice. Confirm every rate, fee and payment with your lenders before consolidating.
Your current debts
Add each debt you want to roll into one loan.
Consolidation loan
One new loan that pays off every debt above.
The debt consolidation calculator compares your current debts against one new consolidation loan. List each balance, its APR and its minimum payment, then enter a new loan rate and term. The tool totals your balances, works out your balance-weighted average APR, and uses the standard amortization formula to find the single new monthly payment, the new total interest and how your monthly cash flow changes. It compares the new loan cost and payment against your current minimums, not a guaranteed lifetime saving, because interest on your current debts depends on how fast you clear them.
What is the Debt Consolidation Calculator?
Debt consolidation means replacing several debts with one new loan. Instead of juggling a credit card, a store card and a personal loan, each with its own rate and due date, you take a single loan large enough to pay them all off and then make one fixed payment. The appeal is usually a lower rate, a lower monthly payment, or simply the simplicity of one bill. This calculator shows all three effects at once so you can judge whether consolidating actually helps your situation.
The first number to understand is your weighted average APR. It is not the simple average of your rates, it is each rate weighted by how much you owe on that debt. A small balance at a scary 29 percent matters less than a large balance at 15 percent. The formula is sum(balance x APR) divided by sum(balance). If the new loan's APR is clearly below your weighted average, consolidating is likely to save on interest. If it is close or higher, the main benefit is convenience or a lower payment from a longer term, not cheaper borrowing.
The new monthly payment comes from the amortization formula M = P x r / (1 - (1 + r) to the power minus n), where P is your total balance, r is the monthly rate (new APR divided by 12 and by 100), and n is the number of months in the term. A longer term lowers the monthly payment but raises total interest, because you carry the balance for longer. A shorter term does the opposite. This is the key trade-off: a lower payment can feel like a win while quietly costing you more over the life of the loan.
Be careful comparing total interest. The tool can compute the new loan's total interest exactly, because a fixed-rate loan has a fixed schedule. It cannot know the true lifetime interest on your current debts, because that depends entirely on how fast you pay them: pay only the minimums on a credit card and you may pay for years, but pay aggressively and you may finish sooner and cheaper than any consolidation loan. So treat this tool as a comparison of the new loan's cost and payment against your current minimum outflow, not a promise of savings.
When to use it
- Combining several credit cards and loans into one fixed monthly payment.
- Checking whether a new loan APR actually beats your balance-weighted average rate.
- Seeing how much a consolidation loan would lower (or raise) your monthly payment.
- Testing how a longer or shorter loan term changes the payment and total interest.
- Deciding between a balance-transfer card, a personal loan, or staying put.
- Estimating the total interest cost of a consolidation offer before you apply.
How to use the Debt Consolidation Calculator
- Add a row for each current debt with its balance, APR and minimum monthly payment. Use Add another debt for more rows and the x button to remove one.
- Check the totals: the tool shows your combined balance, weighted average APR and combined minimum payment.
- Enter the new consolidation loan APR and the term in months.
- Select Compare my options to see the new monthly payment, new total interest and your monthly cash-flow change.
- Use Copy summary to save or share the numbers, then confirm the offer details with your lender.
Formula & method
Worked examples
Three debts: a credit card of $6,000 at 22.9% APR (min $180), a store card of $2,500 at 27.9% (min $90), and a personal loan of $4,000 at 12.5% (min $130). New consolidation loan at 11.5% APR over 48 months.
- Total balance = 6,000 + 2,500 + 4,000 = $12,500. Combined minimum = 180 + 90 + 130 = $400 per month.
- Weighted average APR = (6,000 x 22.9 + 2,500 x 27.9 + 4,000 x 12.5) / 12,500 = 257,150 / 12,500 = 20.57%.
- Monthly rate r = 11.5 / 100 / 12 = 0.0095833. Term n = 48.
- New payment M = 12,500 x 0.0095833 / (1 - 1.0095833 to the power minus 48) = $326.11.
- New total paid = 326.11 x 48 = $15,653.41, so new total interest = 15,653.41 - 12,500 = $3,153.41.
Result: New payment $326.11/mo (about $73.89 less than the $400 in current minimums), new loan interest $3,153.41.
A single balance of $15,000 across debts averaging around 21%, consolidated into a $15,000 loan at 9% APR over 36 months.
- Total balance P = $15,000. Monthly rate r = 9 / 100 / 12 = 0.0075. Term n = 36.
- New payment M = 15,000 x 0.0075 / (1 - 1.0075 to the power minus 36) = $477.00.
- New total paid = 477.00 x 36 = $17,171.86.
- New total interest = 17,171.86 - 15,000 = $2,171.86.
- Because 9% is well below the roughly 21% weighted average, the interest cost is much lower over a fixed 3-year payoff.
Result: New payment $477.00/mo, new loan interest $2,171.86 over 36 months.
How the loan term changes a $12,500 consolidation loan at 11.5% APR
| Term (months) | Monthly payment | Total interest |
|---|---|---|
| 24 | $585.50 | $1,552.09 |
| 36 | $412.20 | $2,339.20 |
| 48 | $326.11 | $3,153.41 |
| 60 | $274.91 | $3,994.46 |
When consolidation tends to help, and when it may not
| Situation | Likely result |
|---|---|
| New APR well below your weighted average | Lower interest and often a lower payment |
| New APR near your weighted average | Mainly simpler bills, little interest saving |
| Longer term than your current payoff pace | Lower payment but more total interest |
| Origination or balance-transfer fees added | Real cost rises, compare after fees |
| You keep using the paid-off cards | New debt can undo the whole plan |
Common mistakes to avoid
- Chasing a lower payment from a longer term. Stretching the loan over more months lowers the monthly payment but increases the total interest you pay. A smaller bill is not the same as cheaper debt. Check the total interest, not just the payment.
- Comparing against a made-up current interest total. The lifetime interest on your current debts depends on how fast you pay them, which is not fixed. This tool compares the new loan cost and payment to your current minimums, so do not read the result as a guaranteed saving.
- Ignoring fees on the new loan. Many consolidation loans and balance-transfer cards charge an origination or transfer fee, often 1 to 5 percent. That fee raises the real cost, so factor it in before deciding the new loan is cheaper.
- Running the old balances back up. Consolidating pays off your cards, but the cards still work. If you keep spending on them you end up with the new loan plus fresh card debt, which is worse than where you started.
Glossary
- Debt consolidation
- Replacing several debts with one new loan so you make a single monthly payment instead of many.
- APR
- Annual Percentage Rate, the yearly cost of borrowing. Divided by 12 it gives the monthly rate used to work out interest.
- Weighted average APR
- Your overall rate across all debts, each APR weighted by its balance: sum(balance x APR) divided by sum(balance).
- Amortization
- Paying off a loan in equal installments where each payment covers interest first and then reduces the principal.
- Term
- The length of the loan in months. A longer term lowers the monthly payment but raises total interest.
- Principal
- The amount borrowed, here the total balance of the debts being consolidated, before interest is added.
Frequently asked questions
What does a debt consolidation calculator do?
It compares your current debts to a single consolidation loan. You enter each balance, APR and minimum payment plus a new loan rate and term, and it returns your total balance, weighted average APR, the new monthly payment, the new total interest, and how your monthly payment changes.
Does consolidating debt actually save money?
Only if the new loan APR is meaningfully below your weighted average APR and you do not stretch the term so far that extra interest cancels the benefit. Consolidation can also just simplify your bills or lower your payment without saving on interest, so check the numbers.
How is the weighted average APR calculated?
It is each debt APR weighted by its balance: multiply every balance by its APR, add those up, then divide by the total of all balances. A large balance influences the average far more than a small one, so it reflects your real blended cost of borrowing.
Why does a longer loan term lower my payment but cost more?
A longer term spreads the same principal over more months, so each payment is smaller. But you carry the balance for longer, and interest accrues each month, so the total interest over the life of the loan is higher. It is a trade between monthly comfort and total cost.
Why does the tool not show the total interest on my current debts?
Because that number is not fixed. The interest you pay on a credit card depends on how fast you pay it down, which can range from a few months to many years. This tool compares the new loan cost and payment against your current minimum payments, not an assumed lifetime total.
Should I include fees in the calculation?
The calculator uses the loan amount you enter. If your consolidation loan has an origination fee or a balance-transfer card charges a transfer fee, add that cost to the balance or treat the result as slightly optimistic, since fees raise the true cost of consolidating.