By default Gtmhub calculates the progress of an Objective, by summing up the attainment of all Key Results and then dividing it by the number of Key Results. In other words, by calculating their average attainment. For the majority of cases, this is the best way to go.

There are, however, cases when the logic for attainment calculation should be different. For example, some companies have top-level Objectives that don't have Key Results. They have child sub-Objectives instead. For example, a department Objective is broken down to several divisions that have each added a sub-Objective, corresponding to their function. In such cases, the top-level Objective attainment must be calculated as the average of the attainment of all child Objectives.

To facilitate such scenarios, Gtmhub enables you to define custom Objective attainment formulas. In addition to the default calculation mechanism, you can also use an attainment formula calculating the average of the Objective's child Objectives

### Configure the progress calculation formula

To select which formula to use for calculating your objective's attainment, follow these steps:

- Create an Objective (or edit an existing Objective)
- Use the
*Progress calculation*dropdown to select the desired calculation formula.

**NOTE**: If you select *Average of child sub-objectives* progress calculation formula, you will no longer be able to add Key Results under this objective. You will be prompted to add Sub-Objectives instead.

### Change the progress calculation formula on existing Objectives

If you have created an Objective, that uses the default progress calculation formula (*Average of key results*), and you change it to *Average of child sub-objectives*, you can no longer have Key Results under this Objective*. *The platform will display a warning message. If you proceed with this step, any KRs created under this Objective will be deleted. This way you have switched to calculation based on sub-objectives and you can add start adding them.

The following video demontrates switching to *Average of child sub-objectives* progress calculation for an existing Objective and how this affects its attainment: