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Monthly vs annual insurance premium calculator

Written and reviewed by Sanjeev Yoganathan · Last reviewed 10 June 2026

Compare the true cost of paying your insurance premium monthly versus annually. Monthly instalments often carry an implied APR — this tool calculates it.

Note: We don't store what you type, and we never ask for medical or sensitive personal details.

Assumptions and methodology

Extra cost = 12 × monthly premium − annual premium. Implied APR is found by solving for the interest rate in a 12-payment loan equation using bisection (numeric root-finding). A positive APR means monthly payments cost more than paying upfront.

Common mistakes to avoid

  • Assuming 0% APR just because the insurer doesn't call it a loan — monthly instalment plans often have an implicit interest charge.
  • Not checking whether the monthly and annual figures cover the same policy terms.
  • Forgetting that some insurers use a third-party credit provider for monthly payments, which may affect your credit file.

Frequently asked questions

Written and reviewed by Sanjeev Yoganathan · Last reviewed 10 June 2026

Disclaimer

This is a simplified estimate based on the assumptions shown above. It isn't a quote, and a real insurer may arrive at a different figure. Use it as a starting point, then check the details with your insurer or adviser.