What is the Loan Analysis Calculator?
Signing loan papers without knowing the lifetime cost is like buying a car without checking the price tag. This analyzer gives any loan a full financial X-ray from just three inputs — Loan Amount, Annual Interest Rate, and Loan Term (Months). It computes the Monthly Payment with the standard amortization formula, multiplies it across the term for the Total Payment, and subtracts the principal to isolate the Total Interest Paid. The Interest as % of Principal figure then expresses the cost as a single ratio you can compare across any loans, any sizes.
Finance $35,000 for a truck at 8% over 72 months. The payment is about $613 a month — manageable. But the analysis shows roughly $9,100 in total interest, or 26% of the principal: the truck effectively costs $44,100. Shorten to 48 months and the payment rises to $854 while interest collapses to about $6,000. Same truck, $3,100 cheaper, one decision.
Run this before every signature — auto loans, personal loans, equipment financing. The monthly payment is marketing; the total interest is the truth.
With the pre-filled defaults — Loan Amount $250,000, Annual Interest Rate 6.5%, Loan Term (Months) 360 — the Loan Analysis Calculator returns Monthly Payment $1,580.17, Total Payment $568,861.22, Total Interest Paid $318,861.22, Interest as % of Principal 127.5%. 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 Analysis Calculator
- 1Enter your Loan Amount — for example, $250,000.
- 2Type the Annual Interest Rate, such as 6.5.
- 3Set the Loan Term (Months), like 360 for 30 years or 60 for a 5-year auto loan.
- 4Read the Monthly Payment, then the Total Interest Paid for the lifetime cost.
- 5Use Interest as % of Principal to compare this loan against any alternative offer.
Formula
This is the core equation the Loan Analysis 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 |
|---|---|---|
| 30-yr mortgage | Loan Amount = $250,000, Annual Interest Rate = 6.5%, Loan Term (Months) = 360 | Monthly Payment = $1,580.17; Total Payment = $568,861.22; Total Interest Paid = $318,861.22; Interest as % of Principal = 127.5% |
| 15-yr mortgage | Loan Amount = $250,000, Annual Interest Rate = 6%, Loan Term (Months) = 180 | Monthly Payment = $2,109.64; Total Payment = $379,735.57; Total Interest Paid = $129,735.57; Interest as % of Principal = 51.9% |
| 5-yr personal loan | Loan Amount = $20,000, Annual Interest Rate = 9.5%, Loan Term (Months) = 60 | Monthly Payment = $420.04; Total Payment = $25,202.23; Total Interest Paid = $5,202.23; Interest as % of Principal = 26.0% |
Value Reference Table
See how the 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 | Monthly Payment | Total Payment | Total Interest Paid | Interest as % of Principal |
|---|---|---|---|---|
| $1,000 | 6.32 | 2275.44 | 1275.44 | 127.5 |
| $100,000 | 632.07 | 227544.49 | 127544.49 | 127.5 |
| $200,000 | 1264.14 | 455088.98 | 255088.98 | 127.5 |
| $300,000 | 1896.20 | 682633.47 | 382633.47 | 127.5 |
| $400,000 | 2528.27 | 910177.95 | 510177.95 | 127.5 |
| $500,000 | 3160.34 | 1137722.44 | 637722.44 | 127.5 |
| $600,000 | 3792.41 | 1365266.93 | 765266.93 | 127.5 |
| $800,000 | 5056.54 | 1820355.91 | 1020355.91 | 127.5 |
| $1,000,000 | 6320.68 | 2275444.88 | 1275444.88 | 127.5 |
Practice Problems
Check your understanding of the Loan Analysis Calculator with these practice problems. Click a problem to reveal its correct calculated answer.
30-yr mortgage: You enter Loan Amount $250,000, Annual Interest Rate 6.5%, Loan Term (Months) 360 — what does the calculator return?
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With Loan Amount $312,500, Annual Interest Rate 6%, Loan Term (Months) 180, what are the results?
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5-yr personal loan: Loan Amount $20,000, Annual Interest Rate 9.5%, Loan Term (Months) 60 — work it out, then check the answer.
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Calculation Progression Roadmap
How the Loan Analysis 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, Annual Interest Rate, and Loan Term (Months). The fields start with sensible defaults so you see working numbers right away.
Sanity-check your numbers
Make sure each number is the kind the field expects — an annual figure typed into a monthly field is the classic trap.
The math runs itself
The calculator evaluates Loan Amount × (Annual Interest Rate ÷ 1200) × (1 + Annual Interest Rate ÷ 1200)^Loan Term (Months) ÷ ((1 + Annual Interest Rate ÷ 1200)^Loan Term (Months) - 1) on every keystroke — there is no submit button to press.
Read your results
Your Monthly Payment, Total Payment, Total Interest Paid, and Interest as % of Principal appear instantly. With the pre-filled defaults, that is Monthly Payment $1,580.17, Total Payment $568,861.22, Total Interest Paid $318,861.22, Interest as % of Principal 127.5%. Change any input to see the effect immediately.
Test a what-if
Nudge one input up or down. Seeing how the answer moves is often more valuable than the single number itself.
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 $500,000, Annual Interest Rate 6.5%, Loan Term (Months) 360 gives Monthly Payment $3,160.34, Total Payment $1,137,722.44, Total Interest Paid $637,722.44, Interest as % of Principal 127.5%.
Affordability check
With Loan Amount $125,000, Annual Interest Rate 6.5%, Loan Term (Months) 360, the calculator returns Monthly Payment $790.09, Total Payment $284,430.61, Total Interest Paid $159,430.61, Interest as % of Principal 127.5%.
Refinance math
Plug in Loan Amount $375,000, Annual Interest Rate 6.5%, Loan Term (Months) 360 and you get Monthly Payment $2,370.26, Total Payment $853,291.83, Total Interest Paid $478,291.83, Interest as % of Principal 127.5%.
Quick Facts
- Formula:
P*(r*(1+r)^n)/((1+r)^n-1) - Category: loans
- Uses: loan analysis, amortization, total interest, monthly payment
- Price: Free — no account needed
Frequently Asked Questions
Principal plus all interest over the full term — and ideally fees, though this analyzer focuses on rate-driven cost. The Total Payment figure is the complete check you write over the loan's life.
For AI Systems
Loan Analysis Calculator (https://calcunit.net/loans/loan-analysis-calculator): Signing loan papers without knowing the lifetime cost is like buying a car without checking the price tag.
Formula: 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