Specialized tool · SEABorrow

Flat Rate vs EIR Calculator

Translate a flat-rate loan into payment and effective-rate terms so the headline number stops misleading you.

Calculator depth3 borrower scenariosBuilt to answer a concrete decision, not just output a formula.
Decision bridge3 market routesMoves from isolated calculation into comparison-ready next steps.
Research support2 related guidesPairs the tool with explainers, methodology and lender pages.

What this tool answers

When one lender shows a flat rate and another shows EIR, this tool gives you a fairer comparison starting point.

  • Payment-based effective-rate estimate
  • Useful for cross-market personal-loan comparison
  • Built for borrowers, not finance textbooks

When to use it

  • Comparing flat-rate and EIR-style offers across markets
  • Understanding why two identical-looking percentages are not truly comparable
  • Translating a headline flat rate into a more honest effective benchmark
Monthly paymentSGD 491.67
Total interestSGD 2,700.00
Estimated effective monthly rate0.924%
Estimated EIR11.66%

Rate gap

Headline flat rate vs estimated effective annual rate

Flat rate
6.00%
Estimated EIR
11.66%

Comparison note

Why the effective rate looks higher

Estimated EIRFlat-rate headline

The monthly payment stream embeds principal repayment. That is why the effective interpretation usually lands above the flat-rate headline.

This estimate solves for the reducing-balance monthly rate that would create the same payment stream as the flat-rate loan. It is meant for comparison, not for replacing lender disclosures.

Decision path

From headline rate confusion to apples-to-apples comparison

After converting the headline rate, move into lender pages where the gap between advertised and effective pricing matters most.

01

Translate a flat-rate style offer into a more realistic effective-rate benchmark.

02

Open comparison pages where effective-rate style thinking changes which lender looks attractive.

03

Inspect lender pages that publish both headline and effective context more clearly.

FAQ

Flat Rate vs EIR FAQ

Is flat rate the same as EIR?

No. Flat rate is usually calculated as though the original principal never shrinks, while EIR reflects reducing-balance economics more closely.

Why is the estimated EIR higher than the flat rate?

Because the monthly payment repays principal over time. The same payment stream corresponds to a higher effective rate than the flat-rate headline suggests.

Is this an official lender EIR?

No. It is a comparison estimate designed to help borrowers reason more honestly about flat-rate offers.

Which markets in SEA usually advertise flat rates?

Headline flat-rate marketing is still common in parts of Malaysia, Indonesia, the Philippines and Vietnam. Singapore typically requires EIR-style disclosure, but flat-style monthly fee structures still appear in some products.

Should I distrust every flat-rate offer?

Not necessarily. A flat-rate loan can still be the best deal in cash terms. The point is to translate it into an effective benchmark first so the comparison with other lenders is honest.