Enter the billed charge, the payer’s allowed amount and the patient’s cost-share to see the contractual adjustment, insurance payment and patient balance.
How a medical bill actually splits
Every paid claim tells the same four-line story: the provider bills a charge, the payer’s contract knocks it down to an allowed amount, the difference writes off as a contractual adjustment, and the allowed amount splits between the insurance payment and the patient’s share. This calculator walks those lines for any claim — enter the charge, the allowed amount, and the patient’s coinsurance and copay, and every figure updates as you type.
How to use it
- Enter the billed charge from the claim.
- Enter the payer’s allowed amount (from the contract fee schedule or the EOB).
- Enter the coinsurance percentage and any copay.
The formulas
A worked example
A $250 charge with a $180 allowed amount writes off $70 as the contractual adjustment. At 20% coinsurance with the deductible met, the patient owes $36 and insurance pays $144 — and $70 + $36 + $144 reconciles back to the $250 charge, which is exactly the check a biller runs on every EOB line.
Estimates only — payer contracts, plan documents and the EOB are always the source of truth, and nothing here is billing, legal or medical advice. The calculator runs entirely in your browser: no patient data is entered, transmitted or stored.