Prepay vs Pay-As-You-Go Calculator

About this calculator

A prepaid plan trades a lump-sum or subscription commitment for a lower unit price, while pay-as-you-go keeps every unit priced individually but with no upfront exposure. The comparison boils down to a single break-even usage level: below it, the per-unit plan costs less because the fixed price of the bundle goes unused; above it, the prepaid bundle wins because its lower effective rate spreads over more units.

This kind of decision comes up whenever a provider offers a bundle-versus-metered choice — phone or data plans, gym memberships versus day passes, transit passes versus single tickets, or subscription credits versus on-demand purchases. The right call depends not just on average usage but on how much cash you can tie up in the bundle, whether unused allowance rolls over or is lost, and how confident you are in your usage forecast; overestimating usage under a prepaid plan wastes the unused allowance, while underestimating usage under pay-as-you-go leaves you paying more per unit than a bundle would have delivered.

This calculator takes your expected usage, the prepaid bundle's price and included allowance, and the pay-as-you-go per-unit price, then tells you which option is cheaper at your usage level and the exact usage volume where the two plans cost the same.