Copay vs Coinsurance Calculator

About this calculator

A copay is a flat fee you pay for a covered service regardless of its actual cost, while coinsurance is a percentage of the service's cost you pay after meeting your deductible — so your out-of-pocket amount under coinsurance scales with how expensive the service turns out to be, while a copay doesn't. This calculator compares both paths for the same service: your flat copay amount versus (coinsurance rate × the portion of cost above your deductible, once the deductible itself has been paid).

Which option costs less depends heavily on the service price relative to the deductible and coinsurance rate — coinsurance can be cheaper for low-cost visits but far more expensive for a costly procedure or hospitalization. Patients comparing insurance plans during open enrollment, and HR/benefits administrators explaining plan options to employees, use this comparison to understand which cost-sharing structure is more favorable for their typical healthcare usage.