Transform quantities

You can use the transform_quantity option to transform usage before applying the price, which you can use when you want pricing on packages of a product instead of individual units. This allows you to divide the reported usage by a specific number and round the result up or down.

For example, say you have a car rental service and you want to charge customers for each hour they rent a car. In this case, you report usage as a number of minutes.

curl https://api.stripe.com/v1/products \
  -u "
sk_test_BQokikJOvBiI2HlWgH4olfQ2
:" \
  -d name="Car Rental Service"

Create a price for the car rental service product. Charge 10 USD per hour, and round up to charge for a full hour, even if the customer uses only part of the hour.

curl https://api.stripe.com/v1/prices \
  -u "
sk_test_BQokikJOvBiI2HlWgH4olfQ2
:" \
  -d nickname="Car Rental Per Hour Rate" \
  -d unit_amount=1000 \
  -d currency=usd \
  -d "recurring[interval]"=month \
  -d "recurring[usage_type]"=metered \
  -d product={{CAR_RENTAL_SERVICE_PRODUCT_ID}} \
  -d "transform_quantity[divide_by]"=60 \
  -d "transform_quantity[round]"=up

If a customer rents the car for 150 minutes, that customer is charged 30 USD for 3 hours of rental (2 hours and 30 minutes, rounded up).