Network Load Balancer (NLB) supports the payasyougo billing method. This topic describes the billable items and billing rules of NLB.
Billing rules
Item  Description 
Billing rules  The payasyougo billing method allows you to use resources before you pay for the resources. Bills are generated and fees are deducted after each billing cycle. 
Billing cycles and bill generation time 

Billable items of NLB
NLB charges instance fees, LCU fees, and Internet data transfer fees.
Network type  Instance fee  LCU fee  Internet data transfer fee 
Internetfacing  Charged  Charged  Charged 
Internalfacing  Charged  Charged  Not charged 
Starting October 1, 2023, you are charged instance fees for NLB instances.
Instance fee
You are charged NLB instance fees on an hourly basis. The billing cycle is 1 hour. If the usage duration in a billing cycle is less than 1 hour, the usage duration is rounded up to 1 hour. The usage duration refers to the period of time from when an NLB instance is created to when the NLB instance is released.
Instance fee = Instance unit price (USD per hour) × Usage duration (hours)
The prices in the following table are only for reference. The actual prices on the buy page shall prevail.
Billable item  Instance unit price (USD per hour) 
Instance fee  0.02 Note Starting October 1, 2023, you are charged instance fees for NLB instances. 
LCU fee
An LCU is the smallest unit used to measure resources consumed by NLB instances.
LCU usage calculation
NLB charges LCU fees on an hourly basis. The billing cycle is 1 hour. If the usage duration in a billing cycle is less than 1 hour, the usage duration is rounded up to 1 hour.
LCU fee per hour = LCU unit price (USD/LCU) × Number of LCUs consumed per hour
Number of LCUs consumed per hour = max {Number of LCUs for new connections, Number of LCUs for concurrent connections, Number of LCUs for data transfer}
The performance metrics of a single LCU vary based on the protocols of NLB listeners.
TCP listener
Metric
Description
Unit
LCU coefficient
How the number of LCUs consumed per hour is calculated
Number of new connections
The number of new TCP connections processed per second.
Seconds
800
The system collects all CPS values within a billing cycle and then divides the largest CPS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula:
Number of LCUs = Largest CPS value/LCU coefficient
Number of concurrent connections (CONNS)
The number of concurrent TCP connections per minute.
Minutes
100,000
The system collects all CONNS values within a billing cycle and then divides the largest CONNS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula:
Number of LCUs = Largest CONNS value/LCU coefficient
Data transfer
The data transfer over TCP processed by NLB. Unit: GB.
Hours
1 GB
The system divides the total amount of data transfer over TCP within a billing cycle by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula:
Number of LCUs = Total amount of data transfer/LCU coefficient
UDP listener
Metric
Description
Unit
LCU coefficient
How the number of LCUs consumed per hour is calculated
Number of new connections
The number of new UDP connections processed per second.
Seconds
400
The system collects all CPS values within a billing cycle and then divides the largest CPS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula:
Number of LCUs = Largest CPS value/LCU coefficient
Number of CONNS
The number of concurrent UDP connections per minute.
Minutes
50,000
The system collects all CONNS values within a billing cycle and then divides the largest CONNS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula:
Number of LCUs = Largest CONNS value/LCU coefficient
Data transfer
The data transfer over UDP processed by NLB. Unit: GB.
Hours
1 GB
The system divides the total amount of data transfer over UDP within a billing cycle by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula:
Number of LCUs = Total amount of data transfer/LCU coefficient
TCP/SSL listener
Metric
Description
Unit
LCU coefficient
How the number of LCUs consumed per hour is calculated
Number of new connections
The number of new SSL/TCP connections processed per second.
Seconds
50
The system collects all CPS values within a billing cycle and then divides the largest CPS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula:
Number of LCUs = Largest CPS value/LCU coefficient
Number of CONNS
The number of concurrent SSL/TCP connections per minute.
Minutes
3,000
The system collects all CONNS values within a billing cycle and then divides the largest CONNS value by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula:
Number of LCUs = Largest CONNS value/LCU coefficient
Data transfer
The data transfer over TCP/SSL processed by NLB. Unit: GB.
Hours
1 GB
The system divides the total amount of data transfer that uses SSL over TCP within a billing cycle by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula:
Number of LCUs = Total amount of data transfer/LCU coefficient
The number of LCUs that are consumed by an NLB listener per hour is calculated based on the dominant metric. The LCU fee for an NLB instance is the sum of the LCU fees of listeners.
LCU unit price
After the hourly metrics of an NLB instance are converted into LCUs, the hourly LCU consumption is calculated based on the actual usage. The LCU consumption is accurate to 0.000001 LCUs. For example, if you consume 0.1 LCUs in an hour, the LCU fee for the hour is calculated based on the following formula: 0.1 × 0.005 = USD 0.0005.
The prices in the following table are only for reference. The actual prices on the buy page shall prevail.
Billable item  LCU unit price (USD per hour) 
LCU  0.005 
LCU billing examples
Alice created a paybyLCU NLB instance in the China (Hangzhou) region at 08:10:00 (UTC+8) on November 2, 2022, and configured TCP and UDP listeners for the NLB instance. Alice released the NLB instance at 08:50:00 (UTC+8) on November 2, 2022. The following table describes the largest CPS value, the largest CONNS value, and the total amount of data transfer of the NLB instance from 08:10:00 (UTC+8) to 08:50:00 (UTC+8).
Metric  TCP  UDP 
CPS per second  The largest CPS value within the hour is 4,000. The number of LCUs is calculated by using the following formula:
 The largest CPS value within the hour is 2,000. The number of LCUs is calculated by using the following formula:

CONNS per minute  The largest CONNS value within the hour is 720,000. The number of LCUs is calculated by using the following formula:
 The largest CONNS value within the hour is 420,000. The number of LCUs is calculated by using the following formula:

Data transfer per hour  The data transfer over TCP processed by NLB within the hour is 10 GB. The number of LCUs is calculated by using the following formula:
 The data transfer over UDP processed by NLB within the hour is 8 GB. The number of LCUs is calculated by using the following formula:

In this example, the metric for which the TCP listener consumes the largest number of LCUs is data transfer (10.0 LCUs), and the metric for which the UDP listener consumes the largest number of LCUs is the number of concurrent connections (8.4 LCUs).
LCU fee per hour for the TCP listener = USD 0.005 × 10.0 = USD 0.05
LCU fee per hour for the UDP listener = USD 0.005 × 8.4 = USD 0.042
LCU fee for the NLB instance per hour = LCU fee for the TCP listener per hour + LCU fee for the UDP listener per hour = USD 0.05 + USD 0.042 = USD 0.092
Estimate LCU consumption
You can use the NLB LCU Calculator to estimate the number of LCUs consumed by your NLB service.
Internet data transfer fee
You are not charged Internet data transfer fees if you use internalfacing NLB instances. You are charged Internet data transfer fees only if you use Internetfacing NLB instances. Internetfacing NLB instances use EIPs to provide services over the Internet. NLB charges instance fees and bandwidth or data transfer fees for the EIPs. For more information, see Payasyougo.