# How Solver Usage is Charged¶

D-Wave charges you for time that solvers run your problems, with rates depending on QPU usage. You can see the rate at which your account’s quota is consumed for a particular solver in the solver’s quota_conversion_rate property.

You can see the time you are charged for in the responses returned for your submitted problems. The relevant field in the response depends on the solver:

• QPU solvers: 'qpu_access_time'. The example in QPU Timing Information from SAPI shows 'qpu_access_time': 9687 in the returned response, meaning almost 10 milliseconds are being charged.
• Hybrid solvers: 'charge_time'. The example in Leap’s Hybrid Solvers’ Timing Information shows 'charge_time': 2991424 in the returned response, meaning almost 3 seconds are being charged.

For example, for a QPU solver with a quota conversion rate of 1, a problem that results in a 'qpu_access_time': 1500, deducts 1.5 milliseconds seconds from your account’s quota.