The PurpleAir API uses a points-based billing system. API calls consume points, and if you do not have enough points to make an API call, the API will return an error.

The points pricing table can be found below. The more points you purchase the more value you will get per dollar. The left column shows the price ranges and the right column shows the number of points you’ll receive per dollar.

Purchase Amount | Points Per USD |
---|---|

$10 - $49 | 100,000 per USD |

$50 - $249 | 150,000 per USD |

$250 - $499 | 200,000 per USD |

$500 - $999 | 300,000 per USD |

$1,000 - $4,999 | 500,000 per USD |

$5,000+ | 1,000,000 per USD |

If you spend $52, you will get 7.8 million points. This is because each dollar is worth 150,000 points at that price.

$52 x 150,000 = 7,800,000 points

The points you purchase will be applied to your “Organization.” You need to move the points into a “Project” before they can be used. More information is found here.

*These values are subject to change. Please refer to develop.purpleair.com for the most current ranges. Feedback is welcome.*

## One Million Starting Points

New users start with one million points. The following two sections show examples of how much data one million points can download.

### Real-Time Data Example

This example will get the real-time “pm2.5” field every 10 minutes for a single sensor.

Using the “get_sensor” endpoint costs 1 point. The “pm2.5” field costs 2 points each time it is collected.

Getting the data every 10 minutes will result in 144 requests being made a day (1440 minutes in a day / 10 minute average).

To calculate the number of points spent daily, we need to add the cost of the endpoint to the cost of the fields. That number will then be multiplied by the number of sensors and the number of requests made daily. The final equation would look as follows:

`(get_sensor + pm2.5) x 1 sensor x 144 daily requests = number of points spent daily`

`(1 + 2) x 1 x 144 = 432 points spent daily`

To see how quickly this request will use the one million starting points, we divide one million by the number of points spent daily.

1,000,000 / 432 gives you 2,314 days of data, which is the same as 6.3 years of data.

### Historical Data Example

This example will get the historical data for ten sensors from January 1, 2022, to January 1, 2023. The fields collected will be “pm2.5_atm_a”, “pm2.5_atm_b”, “pm2.5_cf_1_a”, “pm2.5_cf_1_b”, and “temperature.” The example will also collect 60-minute (1-hour) averages.

The “get_sensor_history” endpoint costs 2 points to use. The total cost of the fields is 6 points per row (the “temperature” field costs 2 points because it is an average of two channels, while all of the other fields cost 1 point).

The PurpleAir Data Download Tool can create a cost estimate for historical requests. If you want to know the cost of a specific request, we recommend using this tool.

Detailed pricing can be enabled in the PurpleAir Data Download Tool by checking the checkbox next to “Show Detailed Points Cost” on the “Settings” page.

Using this tool, we can see that this request will make 270 API calls per sensor. The total cost of the requests per sensor will be 540 points (270 API calls * 2 points per request).

The PurpleAir Data Download Tool also shows us that each sensor will return 8,760 rows of data. This means the cost for all the rows per sensor is 52,560 points (8,760 rows * 6 points per row).

Now that we have both totals, we multiply them by the number of sensors. The total cost for all requests is 5,400 points (540 points * 10 sensors), and the total cost for all rows is 525,600 points (52,560 points * 10 sensors). Adding these two numbers together brings us to the total cost for our request: 531,000 points.

Collecting these five fields with a 60-minute average for a full year of data will spend just over half of the free one million starting points. Changing the time period to two years or lowering the average to 30-minute would bring the total to 1,061,800, just above the starting one million points.

## Learn More

You can learn how to optimize your API usage.

Learn more about purchasing points and how to navigate the Online Dashboard.