Classic Load Balancer (CLB) supports the payasyougo billing method. You can release a payasyougo CLB instance anytime.
Billing rules
Item  Description 

Billing method  The payasyougo billing method allows you to use resources before you pay for them. Bills are generated and fees are deducted after each billing cycle. 
Scenarios  The payasyougo billing method is ideal for the following scenarios:

Billing cycle  Fees are calculated on an hourly basis (UTC+8). After fees are calculated, a new billing cycle begins. For example, if you create a payasyougo CLB instance at 09:30:00 (UTC+8) and release the CLB instance at 12:30:00 (UTC+8), you are charged for 4 hours.
Note If the total amount of your account balance and the vouchers in your Alibaba Cloud account is less than the fee that you need to pay, you are notified by text message or email. 
Configuration changes 
The following figure shows the metering methods of payasyougo CLB instances and whether you can change the metering method.

Effective time of configuration changes  If you change the configuration of a CLB instance, but do not change the metering method of Internet data transfer, the change immediately takes effect. If you change the configuration of a CLB instance, and also change the metering method of Internet data transfer, the changes take effect at 00:00:00 (UTC+8) on the next day. 
Maximum bandwidth 

Specification fee and LCU fee
Specification fee
You are charged specification fees only for paybyspecification CLB instances. The following section describes the metrics of highperformance CLB instances. The performance of a CLB instance varies based on the specification.
 Maximum number of connections
The maximum number of connections that can be established to a CLB instance. When the number of existing concurrent connections reaches the upper limit, new connection requests are dropped.
 Connections per second (CPS)
The maximum number of new connections that can be established to a CLB instance per second. When the actual number reaches the upper limit, new connection requests are denied.
 Queries per second (QPS)
The maximum number of HTTP or HTTPS requests that can be processed per second. This metric is specific to Layer 7 listeners. When the actual number reaches the upper limit, new requests are denied.
Specification  Maximum number of connections  CPS  QPS  Unit price in the Chinese mainland and China (Hong Kong) (USD/hour)  Unit price outside China (USD/hour) 

Specification 1: Small I (slb.s1.small)  5000  3000  1000  0.01  0.012 
Specification 2: Medium I (slb.s2.small)  50,000  5,000  5,000  0.05  0.06 
Specification 3: Medium II (slb.s2.medium)  100,000  10,000  10,000  0.10  0.12 
Specification 4: Large I (slb.s3.small)  200,000  20,000  20,000  0.20  0.24 
Specification 5: Large II (slb.s3.medium)  500,000  50,000  30,000  0.31  0.37 
Specification 6: Super Large I (slb.s3.large)  1,000,000  100,000  50,000  0.51  0.61 
Example: You purchased an Internetfacing CLB instance of the slb.s2.small specification at 10:00:00 (UTC+8) on January 20, 2022 in the China (Hangzhou) region and released the CLB instance at 12:34:00 (UTC+8) on January 21, 2022. The specification fee is calculated by using the following formula:
Unit price of the slb.s2.small specification in the China (Hangzhou) region: USD 0.05 per hour.
Usage duration = 27 hours
Specification fee = USD 0.05 per hour × 27 hours = USD 1.35
LCU fee
A Load Balancer Capacity Unit (LCU) is the smallest unit used to measure resources consumed by CLB instances.
LCU usage
CLB 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 based on new connections per hour, Number of LCUs based on concurrent connections per hour, Number of LCUs based on data transfer per hour, Number of LCUs based on rule evaluations per hour}
An LCU measures the dimensions on which CLB processes traffic. The performance metrics of a single LCU vary based on the protocol of CLB listeners.
 TCP traffic
Metric Description Unit LCU coefficient Calculation Number of new connections (CPS) 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 highest 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 = Highest CPS value/LCU coefficient
Number of concurrent connections (CONNS) The number of concurrent TCP connections per minute. Minute 100,000 The system collects all CONNS values within a billing cycle and then divides the highest 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 = Highest CONNS value/LCU coefficient
Data transfer The data transfer over TCP processed by CLB. Unit: GB. Hour 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 traffic
Metric Description Unit LCU coefficient Calculation CPS 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 highest 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 = Highest CPS value/LCU coefficient
CONNS The number of concurrent UDP connections per minute. Minute 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 = Highest CONNS value/LCU coefficient
Data transfer The data transfer over UDP processed by CLB. Unit: GB. Hour 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
 HTTP and HTTPS traffic
Metric Description Unit LCU coefficient Calculation Number of new connections The number of new HTTP and HTTPS connections processed per second. Seconds 25 The system collects all CPS values within a billing cycle and then divides the highest 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 = Highest CPS value/LCU coefficient
Number of concurrent connections The number of concurrent HTTP and HTTPS connections per minute. Minute 3,000 The system collects all CONNS values within a billing cycle and then divides the highest 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 = Highest CONNS value/LCU coefficient
Data transfer The data transfer over HTTP and HTTPS processed by CLB. Unit: GB. Hour 1 GB The system divides the total amount of data transfer over HTTP and HTTPS 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
Number of rule evaluations The product of the number of forwarding rules processed by CLB and the number of queries per second (QPS). You can use 25 forwarding rules free of charge. If the number of forwarding rules processed by CLB is greater than 25, the following formula is applied: Number of rule evaluations = QPS × (Number of forwarding rules processed by CLB  25). If the number of forwarding rules is less than 25, the following formula is applied: Number of rule evaluations = QPS. Seconds 1,000 The system collects the number of forwarding rules and all QPS values within a billing cycle and uses the highest QPS value to calculate the number of rule evaluations. Then, the system divides the number of rule evaluations by the LCU coefficient to calculate the number of LCUs. The number of LCUs is calculated by using the following formula: Number of LCUs = Number of rule evaluations/LCU coefficient
The number of LCUs that are consumed by a CLB listener per hour is equal to the highest number of LCUs consumed on different metrics. The LCU fee of a single CLB instance is the sum of the LCU fees of each listener.
LCU unit price
Billable items  LCU unit price (USD/hour per LCU) 

LCU  0.007 
Billing examples
You created a paybyLCU CLB instance in the China (Hangzhou) region at 08:10:00 (UCT+8) on June 8, 2022, and configured TCP and HTTP listeners for the CLB instance. You released the CLB instance at 08:50:00 (UCT+8) on June 8, 2022. The following table describes the highest CPS value, the highest CONNS value, the total amount of data transfer, and the largest number of rule evaluations of the CLB instance from 08:10:00 (UTC+8) to 08:50:00 (UTC+8).  
Metric  TCP  HTTP 
CPS (second)  The highest CPS value within the hour is 1,600. The number of LCUs is calculated by using the following formula:
 The highest CPS value within the hour is 100. The number of LCUs is calculated by using the following formula:

CONNS (minute)  The highest CONNS value within the hour is 480,000. The number of LCUs is calculated by using the following formula:
 The highest CONNS value within the hour is 12,000. The number of LCUs is calculated by using the following formula:

Data transfer per hour  The data transfer over TCP processed by CLB within the hour is 4 GB. The number of LCUs is calculated by using the following formula:
 The data transfer over HTTP processed by CLB within the hour is 3.6 GB. The number of LCUs is calculated by using the following formula:

Number of rule evaluations per second  0  Assume that 40 forwarding rules are created for the HTTP listener, and the highest QPS value within the hour is 400. In this example, the number of forwarding rules that you configured exceeds the free quota. The largest number of rule evaluations within the hour is calculated by using the following formula: The number of LCUs is calculated by using the following formula:

In this example, the TCP listener consumes the largest number of LCUs (five LCUs) on concurrent connections. The HTTP listener consumes the largest number of LCUs (six LCUs) on rule evaluations. The number of LCUs consumed each hour is rounded up to the nearest integer. 
LCU fee for the TCP listener = USD 0.007 × 5 = USD 0.035
LCU fee for the HTTP listener = USD 0.007 × 6 = USD 0.042
LCU fee for the CLB instance = LCU fee for the TCP listener + LCU fee for the HTTP listener = USD 0.035 + USD 0.042 = USD 0.077
The average monthly LCU fee for the CLB instance can be calculated by using the following formula: USD 0.077 × 24 × 30 = USD 55.44
Metering methods
Network type  Metering method for data transmission over the Internet  Performance  Instance fee  Specification fee and LCU fee  Fee for data transmission over the Internet  
Specification fee  LCU fee  Data transfer fee  Bandwidth fee  
Internetfacing  Paybydatatransfer  Determined by the specification that you purchase. The largest specification that you can select is s3.large.  ✓  ✓    ✓   
Paybybandwidth  Determined by the specification that you purchase. The largest specification that you can select is s3.large.  ✓  ✓      ✓  
Internalfacing    Determined by the specification that you purchase. The largest specification that you can select is s3.large.    ✓       
Network type  Metering method for data transmission over the Internet  Performance  Instance fee  Specification fee and LCU fee  Fee for data transmission over the Internet  
Specification fee  LCU fee  Data transfer fee  Bandwidth fee  
Internetfacing  Paybydatatransfer  Automatically scales on demand. The upper limit is defined in the s3.large specification.  ✓    ✓  ✓   
Internalfacing    Automatically scales on demand. The upper limit is defined in the s3.large specification.      ✓     
Instance fee
 Billing description
You are charged instance fees for CLB on an hourly basis. If you use a CLB instance for less than 1 hour in a billing cycle, the usage duration is rounded up to 1 hour. The usage duration refers to the period of time from when a CLB instance is created to when the CLB instance is released.
Note You are not charged instance fees for internalfacing CLB instances.  Formula
Instance fee = Instance unit price (USD/hour) × Usage duration (hours)
 Pricing
Click to view the unit prices in different regions. The prices listed in the following table are for reference only. The actual prices on the buy page shall prevail.
Region Instance unit price (USD/hour) China (Hangzhou), China (Shanghai), China (Qingdao), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Shenzhen), China (Heyuan), and China (Chengdu) 0.003 China (Hong Kong), Japan (Tokyo), UAE (Dubai), and South Korea (Seoul) 0.009 US (Silicon Valley) and US (Virginia) 0.005 Singapore (Singapore), Malaysia (Kuala Lumpur), Indonesia (Jakarta), India (Mumbai), UK (London), Germany (Frankfurt), Australia (Sydney), and Thailand (Bangkok) 0.006  Example
You purchased an Internetfacing CLB instance at 10:00:00 (UTC+8) on January 20, 2022 in the China (Hangzhou) region and released the CLB instance at 12:34:00 (UTC+8) on January 21, 2022. The instance fee is calculated by using the following formula:
Instance unit price in the China (Hangzhou) region: USD 0.003 per hour Usage duration = 27 hours Instance fee = USD 0.003 per hour × 27 hours = USD 0.081
Internet data transfer fee
Data transfer fee (charged for paybydatatransfer Internetfacing instances)
 Billing description
You are charged for outbound data transfer over the Internet. You are not charged for inbound data transfer over the Internet. You are charged and billed for paybydatatransfer Internetfacing CLB instances on an hourly basis. If the usage duration is less than 1 hour in a billing cycle, the usage duration is rounded up to 1 hour.
 Formula
Within one billing cycle: Data transfer fee = Unit price of data transfer (USD/GB) × Amount of data transfer (GB)
 Pricing
Click to view data transfer unit prices. The prices listed in the following table are for reference only. The actual prices on the buy page shall prevail.
Region Data transfer unit price (USD/GB) China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Shenzhen), and China (Heyuan) 0.125 China (Qingdao) 0.113 China (Hong Kong) 0.156 US (Silicon Valley) and US (Virginia) 0.078 Malaysia (Kuala Lumpur) 0.112 Singapore (Singapore), Indonesia (Jakarta), India (Mumbai), and Thailand (Bangkok) 0.117 Japan (Tokyo) 0.087 Germany (Frankfurt) and UK (London) 0.070 UAE (Dubai) 0.447 Australia (Sydney) 0.096 South Korea (Seoul) 0.123  Example
You purchased an Internetfacing paybydatatransfer CLB instance at 10:00:00 (UTC+8) on January 20, 2022 in the China (Hangzhou) region and released the CLB instance at 12:34:00 (UTC+8) on January 21, 2022. The outbound data transfer over the Internet is 5 GB.
Unit price of data transfer in the China (Hangzhou) region: USD 0.125 per GB Outbound data transfer: 5 GB Data transfer fee = USD 0.125 per GB × 5 GB = USD 0.625
Bandwidth fee (charged for paybybandwidth Internetfacing instances)
 Billing description
You are charged and billed for paybybandwidth Internetfacing CLB instances on an hourly basis. If the usage duration is less than 1 hour in a billing cycle, the usage duration is rounded up to 1 hour. If the usage duration is less than one day, you are charged for the number of hours that you use a CLB instance. The usage duration is the duration when a CLB instance uses bandwidth.
 The bandwidth fee of an Internetfacing CLB instance is calculated based on a tiered pricing model with 5 Mbit/s as the standard bandwidth value.
 If you modified the maximum bandwidth of a CLB instance within a billing cycle, you are charged based on the highest maximum bandwidth on that day.
NoteFor paybybandwidth CLB instances, the maximum inbound bandwidth is the same as the maximum outbound bandwidth.
 Formula
For a CLB instance whose maximum bandwidth is from 1 to 5 Mbit/s, the bandwidth fee is calculated by using the following formula: Bandwidth fee = Maximum bandwidth × Bandwidth unit price × Usage duration. For a CLB instance whose maximum bandwidth is higher than 5 Mbit/s, the bandwidth fee is calculated by using the following formula: Bandwidth fee = [5 × Unit price of bandwidth from 1 to 5 Mbit/s + (Maximum bandwidth  5) × Unit price of bandwidth higher than 5 Mbit/s] × Usage duration.
 Pricing
Click to view bandwidth unit prices. The prices listed in the following table are for reference only. The actual prices on the buy page shall prevail.
Region Unit price of bandwidth from 1 to 5 Mbit/s (USD/hour) Unit price of bandwidth from 1 to 5 Mbit/s (USD/day) Unit price of bandwidth higher than 5 Mbit/s (USD/hour) Unit price of bandwidth higher than 5 Mbit/s (USD/day) China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Shenzhen), China (Heyuan), and China (Chengdu) 0.006 0.144 0.02 0.48 China (Qingdao) 0.005 0.12 0.016 0.384 China (Hong Kong) 0.006 0.144 0.02 0.48 Singapore (Singapore), Indonesia (Jakarta), India (Mumbai), Malaysia (Kuala Lumpur), Germany (Frankfurt), UK (London), Australia (Sydney), Thailand (Bangkok), and South Korea (Seoul) 0.006 0.144 0.02 0.48 Japan (Tokyo) 0.007 0.168 0.023 0.552 UAE (Dubai) 0.048 11.52 0.118 2.832 US (Silicon Valley) and US (Virginia) 0.006 0.144 0.02 0.48  Example
You purchased a 2 Mbit/s Internetfacing CLB instance in the China (Hangzhou) region at 10:00:00 (UTC+8) on January 20, 2022 and changed the maximum bandwidth to 20 Mbit/s at 08:00:00 (UTC+8) on January 21, 2022. Then, you released the CLB instance at 12:34:00 (UTC+8) on January 21, 2022. The bandwidth fees are calculated by using the following formulas:
Maximum bandwidth on the day when you purchased the CLB instance: 2 Mbit/s Maximum bandwidth on the day when you modified the maximum bandwidth of CLB instance: 20 Mbit/s Bandwidth fee for the first day: (2 × 0.006) × 14 = USD 0.168 Bandwidth fee for the next day: [5 × 0.006 + (20  5) × 0.02] × 13 = USD 4.29 Total fee = 0.168 + 4.29 = USD 4.458