How this calculator works
Each loan's rate is weighted by its balance: multiply every balance by its rate, add those up and divide by the total balance. Federal Direct Consolidation rounds this up to the nearest one-eighth of a percent.
Worked example
With the example values below: Weighted average rate, 6.227% (across 3 loans). Change any number above to run your own.
What you enter
| Input | Example |
|---|---|
| Loan 1 | |
| Balance | $12,000 |
| Rate | 4.99% |
| Loan 2 | |
| Balance | $8,000 |
| Rate | 6.54% |
| Loan 3 | |
| Balance | $15,000 |
| Rate | 7.05% |
| Loan 4 | |
| Balance | $0 |
| Rate | 0% |
What a weighted average rate is
When you have several loans at different rates, a simple average of the rates is misleading because larger balances matter more. The weighted average multiplies each balance by its rate, adds the results and divides by the total balance, so each loan counts in proportion to its size.
For example, $12,000 at 4.99%, $8,000 at 6.54% and $15,000 at 7.05% total $35,000. The weighted average is about 6.20%, even though the simple average of the three rates is 6.19%; with different balances, the gap can be much larger.
How federal consolidation uses it
A federal Direct Consolidation Loan takes the weighted average rate of the loans you combine and rounds it up to the nearest one-eighth of a percent. That becomes the fixed rate on the new loan. Consolidation doesn't lower your rate; at best it keeps it about the same.
The calculator shows both the exact weighted average and the rounded consolidation rate. See the student loan consolidation calculator for the new payment and term.
Using it to compare refinance offers
The weighted average is the number a refinance offer needs to beat. If your weighted rate is 6.2% and a lender offers 5.5% on the same term, you'll pay less interest. If the offer is 6.3%, refinancing only helps if it changes the term in a way you want.
Compare offers in the student loan refinance calculator, and remember that refinancing federal loans gives up federal benefits.
Other uses
- Finding the overall cost of all your debts, including cards and car loans.
- Deciding whether a debt consolidation loan beats your current mix; see the debt consolidation calculator.
- Spotting which loan to target first with extra payments: any loan above the weighted average is pulling your rate up.
Frequently asked questions
How do you calculate a weighted average interest rate?
Multiply each loan's balance by its rate, add those products together and divide by the total balance. $10,000 at 5% and $5,000 at 8% give (500 + 400) ÷ 15,000 = 6.0%.
Why is the weighted average different from the simple average?
The simple average treats every loan equally. The weighted average gives larger balances more influence, which reflects what you actually pay in interest.
Does federal consolidation round the rate up?
Yes. A Direct Consolidation Loan's rate is the weighted average of the loans being combined, rounded up to the nearest one-eighth of a percentage point.
Does consolidating student loans lower my interest rate?
No. Federal consolidation keeps roughly the same rate, rounded up slightly. Only refinancing with a private lender can lower it, and that gives up federal benefits.
Can I use this for credit cards and other debts?
Yes. The math is the same for any group of debts, which makes it useful for judging whether a consolidation loan or balance transfer offer is actually lower.
Grow what this calculator projects.
TruthSayer AI sends quantitative stock signals across valuations, earnings and dark-pool activity, each one traded in its own funded account first.
Estimates for planning only, not financial, tax or legal advice. Tax tools use 2026 federal figures (brackets, $16,100 / $32,200 standard deduction, $19,000 gift exclusion, $15M lifetime exemption). Rates shown as defaults are examples; replace them with quotes you actually receive.