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Rounding and Precision


Rounding and Precision

Rounding and precision are important aspects with any numerical or financial system, and Zuora is no exception. Understanding how rounding and precision are defined within Zuora will give you insight into how Zuora handles precision, rounding and calculations.


Rounding a numeric value is the act of replacing one numeric value with one that is approximately equal but has a shorter, simpler, or more explicit representation. For example, replacing USD $65.8476 with USD $65.85. Rounding in Zuora takes place with units of measure (UOM) and currency values.

  • UOM (unit of measure): Examples include quantity on a price plan, quantity entered in a subscription, and usage records uploaded in a month.
  • Currency: Examples include price, invoice amount, MRR, and tax total.


Precision of a numeric value describes the number of digits that are used to express that value, including digits to both the left and the right of any decimal point. For example 4.520 has a precision of 4. Zuora supports up to 13 digits to the left of the decimal place, and up to 9 digits to the right.

Currency rounding rules

Currency rounding is defined by the currency itself.

Zuora includes rounding options that you can apply to any individual currency. 

  • Rounding Mode: Allows you to define whether a currency should be rounded DownUp, or Half Up. By default, Zuora uses Half Up rounding on all currencies (for example, where 3.49 is rounded to 3 and 3.50 is rounded to 4). The Down and Up options are useful if you need to use a different rounding mode for a particular currency (for example, in Japan, it is often the case that currency values are rounded Down to the nearest Yen).
  • Rounding Increment: Allows you to define the currency increment used for rounding. This is useful if you are working with currencies that do not round to the nearest cent (for example, Swiss francs are typically rounded to the nearest 5 cents).

By default, any currency that has a greater number of decimal places than defined by the currency will be rounded based on the near rule (half up), with values of 5 or greater being rounded up (using the Half Up setting).

For example, because the Japanese Yen (JPY) does not have a cent in circulation, the lowest value is 1 JPY. When a user enters an amount with decimal places, Zuora will round it to the nearest non-decimal value. For example, if a user enters 15.67, Zuora Billing automatically convert this value to 16.00.

The same is true when activating or editing a currency from within Zuora Billing Settings Customize Currencies: the Decimal Places values are pre-defined based on the decimal places supported by each currency.

Currency rounding on invoices

Zuora rounds the Invoice Line Item Amount (pre-tax) based on the List Price of the product and on the rounding rules that you have set for the currency. Tax is also rounded off in this manner, but is rounded from the value of the Invoice Line Item Amount (pre-tax).

For example: 

  • List Price: 454.5454545 (product rate plan charge) 
  • Invoice Amount (pre-tax): 454.55
    • This is rounded from the List Price.
  • Tax: 45.46
    • This is rounded from the Invoice Amount (pre-tax) 
  • Extended Price: 500.01

If you want to use a List Price that has decimal places, you can remove the 0.01 value offset by processing an adjustment when the invoice has been generated.

Usage rounding rules

A value is rounded based on its predefined rounding rule, and each currency and UOM has a rounding rule associated with it. UOM rounding rules are user-defined, while currency rounding rules are defined by the currencies themselves.

Zuora supports the following rounding rules:

  • Round up (usage only): Any usage amount that has a greater number of decimal places than supported by the UOM will be rounded up to the number of supported decimal places. For example, if the UOM, “Gigabyte,” supports two decimal places and the usage record is created with quantity of 2.334 Gigabytes, when rounded up, the rounded numeric value is 2.34 Gigabytes.
  • Round down (usage only): Any usage amount that has a greater number of decimal places than supported by UOM will be rounded down to the number of supported decimal places. For example, if the UOM “Users” supports no decimal places and a usage record is created with a quantity of 2.334 Users, when rounded down, it will be 2 Users.

Data type rounding rules

There are five data types in Zuora that are either currency or UOM values. Each data type has its own rules for when rounding occurs.

Data Type Examples Rounding Based On
Price Also known as rate, unit price from product catalog, unit price Prices are never rounded, even if precision exceeds currency. For example, a unit price of $3.1235/GB is always stored and calculated as $3.1235.
Amount Extended price (for example, $4.99/user * 4 users), adjustment amount, invoice total, invoice balance, total tax amount. Rounding is based on currency’s defined rounding rules.
Metrics MRR, TCV Rounding is based on currency’s defined rounding rules.
Tax "Tax line items", individual taxation items Tax line items are not rounded. Summed tax line items result in total tax, defined as an amount.
Quantity Default quantity in product catalog, quantity entered on subscription or usage record, quantity displayed on invoices Rounding is based on unit of measure’s rounding rule

Tax rounding rules

  • When tax information is displayed on invoices, rounding applies to tax calculation. For details and examples, see this article
  • With tax-inclusive mode, rounding can happen to the tax amount or the net amount. For details and examples, see this article.

Rounding and "As Is"

Rounding can occur in the following cases:

  • Before a value is stored.
  • Before a value is used in calculations.
  • Before a value is displayed or returned via the API.
  • After values of the same type are aggregated (added) together.

If numbers are not rounded, they are referred to "as is."

Data types rounded "As Is"

The following data types are rounded as is:

Data Type Prior to Storage Prior to Use After Aggregation Prior to Display/API Example
Price As Is As Is N/A As Is $3.479/Gallon
Amount Rounded Rounded Rounded Rounded Extended Price of $36.67, Total Tax of $18.29
Metrics As Is As Is As Is Rounded MRR = $1533.333333333
Tax As Is As Is N/A (aggregated tax items are an amount) As Is Tax item of $12.1275
Quantity (Transaction) Rounded Rounded Rounded Rounded 7.65 GB, 8 users
Quantity (Tier) Rounded Rounded N/A Rounded Volume Pricing for 1-100 Units
Quantity (Other) As Is Rounded Rounded As Is Usage Quantity Entered

Examples of rounding

For example, a fictitious SaaS company sells seat licenses to its software and charges for any storage used. It offers the following monthly rate plan for its product:

Recurring Fee Usage Fee
$59.99/seat license per month $1/GB per month

It has defined the following units of measure:

Unit of measure Number of decimal places Rounding rule
Seat License 0 Round down
Gigabytes 2 Round down

The company also charges sales tax at the rate of 7.775%. A subscription is then created and a quantity of 4.6 is mistakenly entered for the number of seat licenses. Since seat licenses have 0 decimal places and transaction quantities are rounded prior to being stored, 4.6 is rounded to 4 based on its round down rounding rule, and then stored. Any query via the API or display of this value in the UI will return a value of 4.

The usage is subsequently uploaded into the system with a value of 12.31245 GB. Since usage quantity is stored as is, the value 12.31245 is then stored. Any display in the UI or query via the API will return the value of 12.31245. When the invoice is generated, charges are calculated as defined in the following table:

Amount Calculation Total
Recurring Charge Unit price * transaction quantity = $59.99/seat license * 4 seat licenses $239.96
Usage Charge Unit price * usage quantity = $1/GB * Round(12.31245 GB)= $1/GB * 12.32 GB ) $12.32
Tax item on recurring charge Charge * tax rate = $239.96 * 0.0775 $18.5969
Tax item on usage charge UCharge * tax rate = $12.32 * 0.0775 $0.9548
Invoice Total Recurring charge + usage charge + total tax = $239.96 + $12.32 + $19.55 $271.83


Usage quantities (like GB) are not rounded when stored, while transaction quantities (like seat licenses) are rounded when stored. For example, 12.3124 GB is not rounded, while 4.6 seat licenses are stored as 4 seat licenses. Individual tax items are not rounded. When they are aggregated (added together) for a total tax they are then rounded.