You are charged for using Internet NAT gateways. This topic describes the billing method and billable items of Internet NAT gateways.
Overview
Internet NAT gateways support the payasyougo billing method.
Formula
Total fee = Instance fee + CU fee
 You are charged for the amount of resources that you use in each billing cycle. Bills are generated and fees are deducted from your account balance on a regular basis. The billing cycle of Internet NAT gateways is 1 hour. Bills are generated and fees are deducted on an hourly basis.
 After you delete an Internet NAT gateway, the billing immediately stops. For more information about how to delete an Internet NAT gateway, see Delete an Internet NAT gateway.
 Internet NAT gateways can withstand traffic spikes. The following table describes
the performance metrics of Internet NAT gateways.
Specification Number of maximum connections Maximum number of new connections Throughput Default 2,000,000 100,000 5 Gbps Maximum quota that you can apply for by submitting a ticket 10,000,000 1,000,000 100 Gbps
Payasyougo
Total fee of a paybyCU Internet NAT gateway = Instance fee + CU fee
Instance fee
Instance fee = Unit price of an Internet NAT gateway(USD/hour) × Usage duration (hours)
The usage duration is the period from the time when the Internet NAT gateway is created to the time when the Internet NAT gateway is deleted.
Region  Unit price(USD/hour) 

China (Hangzhou), China (Shanghai), China (Qingdao), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Shenzhen), China (Heyuan), China (Guangzhou), and China (Chengdu)  0.034 
China (Hong Kong), Japan (Tokyo), South Korea (Seoul), Singapore (Singapore), Australia (Sydney), Malaysia (Kuala Lumpur), Indonesia (Jakarta), Philippines (Manila), Thailand (Bangkok), India (Mumbai), Germany (Frankfurt), UK (London), US (Silicon Valley), US (Virginia), and UAE (Dubai)  0.043 
CU fee
CU fee per hour = CU unit price (USD/CU) × Number of CUs consumed per hour
Number of CUs consumed per hour = Max(Number of CUs based on new connections per hour,
Number of CUs based on concurrent connections per hour, Number of CUs based on data
transfer per hour)CUs measure the dimensions on which an Internet NAT gateway processes traffic. The following table describes the dimensions.
Metric  Unit  CU coefficient  How the number of CUs per hour is calculated 

Connections per second (CPS)  Second  1,000  The system collects all CPS values within a billing cycle and then divides the highest
CPS value by the CU coefficient to calculate the number of CUs. The number of CUs
based on CPS is calculated by using the following formula:

Concurrent connections (CONNS)  Minute  10,000  The system collects all CONNS values within a billing cycle and then divides the highest
CONNS value by the CU coefficient to calculate the number of CUs. The number of CUs
based on CONNS is calculated by using the following formula:

Data transfer (bytes)  Hour  1 GB  The system collects the total amount of data transfer including the inbound and outbound
traffic within a billing cycle. Then, the system divides the total amount by the CU
coefficient to calculate the number of CUs.
Note The amount of outbound and inbound network traffic collected by the system equals
the amount of network traffic to be processed by a NAT gateway.

Region  Unit price of CU(USD/ENI/hour) 

China (Hangzhou), China (Shanghai), China (Qingdao), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Shenzhen), China (Heyuan), China (Guangzhou), and China (Chengdu)  0.034 
China (Hong Kong), Japan (Tokyo), South Korea (Seoul), Singapore (Singapore), Australia (Sydney), Malaysia (Kuala Lumpur), Indonesia (Jakarta), Philippines (Manila), Thailand (Bangkok), India (Mumbai), Germany (Frankfurt), UK (London), US (Silicon Valley), US (Virginia), and UAE (Dubai)  0.043 
Billing example for CU fees
CU fee per NAT gateway per hour = Max{Number of CUs based on new connections per hour, Number of CUs based on concurrent connections per hour, Number of CUs based on the amount of data transferred per hour} × CU unit price
You created three VPC NAT gateways in the Germany (Frankfurt) region at 08:10:00 (UTC+8)
on November 8, 2021. Then, you released them at 08:50:00 (UTC+8) on November 8, 2021.
The following table describes the highest CPS value, the highest CONNS value, and
the total amount of data transfer of the three VPC NAT gateways from 08:10:00 (UTC+8)
to 08:50:00 (UTC+8). Metric  NAT Gateway 1  NAT Gateway 2  NAT Gateway 3 

Highest CPS value (connections/second)  1100  32  0 
Highest CONNS value (connections/minute)  20000  8  0 
Total amount of data transfer (GB/hour)  3.5  0.0056  0 
Number of CUs  NAT Gateway 1  NAT Gateway 2  NAT Gateway 3 

Number of CUs based on CPS  1100÷1000=1.1  32÷1000=0.032  0 
Number of CUs based on CONNS  20000÷10000=2  8÷10000=0.0008  0 
Number of CUs based on data transfer  3.5÷1=3.5  0.0056÷1=0.0056  0 
CU fee (USD)  3.5×0.043=0.1505  0.032×0.043=0.001376  0 
Overdue payments and topups for payasyougo Internet NAT gateways
Parameter  Description 

Overdue payment 

Topup 

Billing of related services
After you create an Internet NAT gateway, you must associate an EIP with the Internet NAT gateway. This enables the Internet NAT gateway to access the Internet. You are charged for the EIPs that are associated with Internet NAT gateways. For more information, see Subscription and Payasyougo.