# Size estimates for real-time segments

• Updated

Optimizely Data Platform (ODP) provides a size estimate for each real-time segment. Providing an estimate rather than a specific calculation allows for segments to calculate in real-time. The date and time that ODP last calculated the size estimates displays at the top of the Real-Time Segments page.

You can also view the size estimate for a specific real-time segment:

For more information on real-time segments in ODP, see Build real-time segments in ODP.

## How ODP calculates size estimates

ODP calculates an estimated lower and upper bound for the number of people that might qualify for each real-time segment.

• When the lower bound is 0, one of the following size estimates displays:
• 0+ People – The segment has conditions but very few or no qualifying customers.
• 0 People – The segment does not have conditions and therefore, no qualifying customers.
• When the lower bound is greater than 0 but less than or equal to 100, ODP displays the lower bound as the size estimate.
• When the lower bound is greater than 100, ODP displays the average between the lower and upper bounds.
For all size estimates less than or equal to 100 people, ODP displays a "+" next to the estimate. For all size estimates greater than 100 people, ODP displays a "" before the estimate.

### Size estimate rounding

When the average between the lower and upper bounds is less than 1,000, the estimate displays with no rounding. For example:

• 46 displays as 46+
• 100 displays as 100+
• 143 displays as ≈ 143
• 921 displays as ≈ 921

For size estimates of 1000 or more, ODP follows standard rounding rules, for example:

• 12,345 displays as 12.3K
• 123,456 displays as 123.5K
• 1,234,567 displays as 1.2M
• 125,456,789 displays as 125.5M
• 1,254,567,899 displays as 1.3B

### Size estimate examples

0+ People

• The segment has conditions
• Lower bound  = 0
• Upper bound = 104,512

0 People

• The segment does not have conditions
• Lower bound  = 0
• Upper bound = 104,512

5+ People

• The segment has conditions
• Lower bound  = 5
• Upper bound = 165,678

≈ 137.4K People

• The segment has conditions
• Lower bound  =42,284
• Upper bound = 232,422
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