Your billing plan is based on one of two credit types: Tests or Virtual User Hours.
The simplest of the two. You will be charged for every test that you run, except for Debug/Sandbox tests that run for 20 Users and up to 20 minutes maximum.
E.g. If a test runs for 50 minutes on 2 engines, 1 Test credit will be billed.
Virtual User Hours:
Blazemeter calculates VUH as follows: Length of test in hours (rounded up to the next hour) * Max Users.
E.g. if a test runs for 90 minutes with 60 virtual users, 2 * 60 = 120 VUHs will be billed.
Note that a test's consumption of VUHs is based on the actual max concurrency and duration of the test. If you configured a one hour test ramping up to 20,000 Virtual Users but stopped it when it reached 10,000 Virtual Users, the test will only consume 10,000 VUHs. If the test was configured for 3 hours but you stopped it after 2 hours it will consume the max concurrency reached X 2 (Hours).
Your remaining test credits, as well as your credit type, can be checked by going to Settings > Accounts > Billing
A summary of the basic plans and what they allow you to do can be found at https://www.blazemeter.com/pricing. If you would like a customized plan, please contact our Sales Accounting department at https://www.blazemeter.com/contact-us#sales