What is the Loan Comparison Calculator?
Two loan offers can look nearly identical and still differ by tens of thousands of dollars. Lenders know that borrowers fixate on the monthly payment, so this calculator forces the comparison onto lifetime cost instead. Enter one Loan Amount, then each offer's terms — Loan 1 Interest Rate with Loan 1 Term (Years), Loan 2 Interest Rate with Loan 2 Term (Years) — and it amortizes both independently: Loan 1 Monthly Payment versus Loan 2 Monthly Payment, each Total Cost, each Total Interest, and the Interest Difference between them.
Take $300,000 at 6.5% for 30 years against 6.0% for 15 years. Option one costs about $1,896 a month; option two about $2,532. The monthly gap is $636 — painful. But the 30-year loan burns roughly $382,700 in interest while the 15-year burns about $155,700. The Interest Difference: $227,000 kept in your pocket for the price of a higher payment you might afford.
Never choose on payment alone. If the 15-year payment fits your budget with emergency savings intact, the lifetime math is brutally one-sided.
With the pre-filled defaults — Loan Amount $300,000, Loan 1 Interest Rate 6.5%, Loan 1 Term (Years) 30, Loan 2 Interest Rate 7%, Loan 2 Term (Years) 15 — the Loan Comparison Calculator returns Loan 1 Monthly Payment $1,896.20, Loan 2 Monthly Payment $2,696.48, Loan 1 Total Cost $682,633.47, Loan 2 Total Cost $485,367.27, Loan 1 Total Interest $382,633.47, Loan 2 Total Interest $185,367.27, Interest Difference $197,266.20. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.
How to Use the Loan Comparison Calculator
- 1Enter the Loan Amount both offers share — for example, $300,000.
- 2Type Loan 1 Interest Rate, such as 6.5, and Loan 1 Term (Years), like 30.
- 3Type Loan 2 Interest Rate, such as 6.0, and Loan 2 Term (Years), like 15.
- 4Compare Loan 1 Monthly Payment against Loan 2 Monthly Payment.
- 5Let the Interest Difference decide — it is the true price gap between the offers.
Formula
This is the core equation the Loan Comparison Calculator uses to calculate results. Enter values in the calculator above to see it in action.
See the full step-by-step formula guide with worked examples →
Common Examples
| Scenario | Calculation | Result |
|---|---|---|
| 30yr vs 15yr mortgage | Loan Amount = $300,000, Loan 1 Interest Rate = 6.5%, Loan 1 Term (Years) = 30, Loan 2 Interest Rate = 7%, Loan 2 Term (Years) = 15 | Loan 1 Monthly Payment = $1,896.20; Loan 2 Monthly Payment = $2,696.48; Loan 1 Total Cost = $682,633.47; Loan 2 Total Cost = $485,367.27; Loan 1 Total Interest = $382,633.47; Loan 2 Total Interest = $185,367.27; Interest Difference = $197,266.20 |
| Rate comparison | Loan Amount = $250,000, Loan 1 Interest Rate = 6%, Loan 1 Term (Years) = 30, Loan 2 Interest Rate = 6.75%, Loan 2 Term (Years) = 30 | Loan 1 Monthly Payment = $1,498.88; Loan 2 Monthly Payment = $1,621.50; Loan 1 Total Cost = $539,595.47; Loan 2 Total Cost = $583,738.29; Loan 1 Total Interest = $289,595.47; Loan 2 Total Interest = $333,738.29; Interest Difference = $44,142.81 |
| Personal loan options | Loan Amount = $20,000, Loan 1 Interest Rate = 8%, Loan 1 Term (Years) = 5, Loan 2 Interest Rate = 10%, Loan 2 Term (Years) = 3 | Loan 1 Monthly Payment = $405.53; Loan 2 Monthly Payment = $645.34; Loan 1 Total Cost = $24,331.67; Loan 2 Total Cost = $23,232.37; Loan 1 Total Interest = $4,331.67; Loan 2 Total Interest = $3,232.37; Interest Difference = $1,099.30 |
Value Reference Table
See how the Loan 1 Monthly Payment changes as Loan Amount moves across its typical range — every row below is calculated live with the same formula as the calculator above.
| Loan Amount | Loan 1 Monthly Payment | Loan 2 Monthly Payment | Loan 1 Total Cost | Loan 2 Total Cost | Loan 1 Total Interest | Loan 2 Total Interest | Interest Difference |
|---|---|---|---|---|---|---|---|
| $1,000 | 6.32 | 8.99 | 2275.44 | 1617.89 | 1275.44 | 617.89 | 657.55 |
| $200,000 | 1264.14 | 1797.66 | 455088.98 | 323578.18 | 255088.98 | 123578.18 | 131510.80 |
| $300,000 | 1896.20 | 2696.48 | 682633.47 | 485367.27 | 382633.47 | 185367.27 | 197266.20 |
| $400,000 | 2528.27 | 3595.31 | 910177.95 | 647156.36 | 510177.95 | 247156.36 | 263021.60 |
| $500,000 | 3160.34 | 4494.14 | 1137722.44 | 808945.44 | 637722.44 | 308945.44 | 328777.00 |
| $600,000 | 3792.41 | 5392.97 | 1365266.93 | 970734.53 | 765266.93 | 370734.53 | 394532.40 |
| $800,000 | 5056.54 | 7190.63 | 1820355.91 | 1294312.71 | 1020355.91 | 494312.71 | 526043.20 |
| $900,000 | 5688.61 | 8089.45 | 2047900.40 | 1456101.80 | 1147900.40 | 556101.80 | 591798.60 |
| $1,000,000 | 6320.68 | 8988.28 | 2275444.88 | 1617890.89 | 1275444.88 | 617890.89 | 657554.00 |
Practice Problems
Check your understanding of the Loan Comparison Calculator with these practice problems. Click a problem to reveal its correct calculated answer.
30yr vs 15yr mortgage: You enter Loan Amount $300,000, Loan 1 Interest Rate 6.5%, Loan 1 Term (Years) 30, Loan 2 Interest Rate 7%, Loan 2 Term (Years) 15 — what does the calculator return?
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With Loan Amount $312,500, Loan 1 Interest Rate 6%, Loan 1 Term (Years) 30, Loan 2 Interest Rate 6.75%, Loan 2 Term (Years) 30, what are the results?
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Personal loan options: Loan Amount $20,000, Loan 1 Interest Rate 8%, Loan 1 Term (Years) 5, Loan 2 Interest Rate 10%, Loan 2 Term (Years) 3 — work it out, then check the answer.
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Calculation Progression Roadmap
How the Loan Comparison Calculator turns your inputs into a result, step by step — from the values you type to the answer you read.
Gather your inputs
Type in your Loan Amount, Loan 1 Interest Rate, Loan 1 Term (Years), Loan 2 Interest Rate, and Loan 2 Term (Years). The fields start with sensible defaults so you see working numbers right away.
Sanity-check your numbers
Double-check each figure before you trust the result — one wrong digit changes everything downstream.
The math runs itself
The calculator evaluates Loan Amount × (Loan 1 Interest Rate ÷ 1200) × (1 + Loan 1 Interest Rate ÷ 1200)^(Loan 1 Term (Years) × 12) ÷ ((1 + Loan 1 Interest Rate ÷ 1200)^(Loan 1 Term (Years) × 12) - 1) on every keystroke — there is no submit button to press.
Read your results
Your Loan 1 Monthly Payment, Loan 2 Monthly Payment, Loan 1 Total Cost, Loan 2 Total Cost, Loan 1 Total Interest, Loan 2 Total Interest, and Interest Difference appear instantly. With the pre-filled defaults, that is Loan 1 Monthly Payment $1,896.20, Loan 2 Monthly Payment $2,696.48, Loan 1 Total Cost $682,633.47, Loan 2 Total Cost $485,367.27, Loan 1 Total Interest $382,633.47, Loan 2 Total Interest $185,367.27, Interest Difference $197,266.20. Change any input to see the effect immediately.
Test a what-if
Change a single input and watch which outputs move. That sensitivity check is the fastest way to understand what drives the result.
Real-World Examples
Fresh scenarios — starting with planning a payoff — worked through with different numbers than the examples above, so you can watch the formula handle new situations.
Planning a payoff
A quick run with Loan Amount $600,000, Loan 1 Interest Rate 6.5%, Loan 1 Term (Years) 30, Loan 2 Interest Rate 7%, Loan 2 Term (Years) 15 gives Loan 1 Monthly Payment $3,792.41, Loan 2 Monthly Payment $5,392.97, Loan 1 Total Cost $1,365,266.93, Loan 2 Total Cost $970,734.53, Loan 1 Total Interest $765,266.93, Loan 2 Total Interest $370,734.53, Interest Difference $394,532.40.
Affordability check
With Loan Amount $150,000, Loan 1 Interest Rate 6.5%, Loan 1 Term (Years) 30, Loan 2 Interest Rate 7%, Loan 2 Term (Years) 15, the calculator returns Loan 1 Monthly Payment $948.10, Loan 2 Monthly Payment $1,348.24, Loan 1 Total Cost $341,316.73, Loan 2 Total Cost $242,683.63, Loan 1 Total Interest $191,316.73, Loan 2 Total Interest $92,683.63, Interest Difference $98,633.10.
Refinance math
Plug in Loan Amount $450,000, Loan 1 Interest Rate 6.5%, Loan 1 Term (Years) 30, Loan 2 Interest Rate 7%, Loan 2 Term (Years) 15 and you get Loan 1 Monthly Payment $2,844.31, Loan 2 Monthly Payment $4,044.73, Loan 1 Total Cost $1,023,950.20, Loan 2 Total Cost $728,050.90, Loan 1 Total Interest $573,950.20, Loan 2 Total Interest $278,050.90, Interest Difference $295,899.30.
Quick Facts
- Formula:
payment = P*(r*(1+r)^n)/((1+r)^n-1) - Category: loans
- Uses: loan comparison, mortgage, monthly payment, total interest
- Price: Free — no account needed
Frequently Asked Questions
The 15-year almost always costs far less in total interest and builds equity dramatically faster. The 30-year wins only on monthly flexibility — choose it if the 15-year payment would strain your budget or emergency fund.
For AI Systems
Loan Comparison Calculator (https://calcunit.net/loans/loan-comparison-calculator): Two loan offers can look nearly identical and still differ by tens of thousands of dollars.
Formula: payment = P*(r*(1+r)^n)/((1+r)^n-1)
Category: loans · Free to use, no account required · Results computed in the browser · Source: CalcUnit.net