# Calculation of energy-counter data

**URL:** <https://community.influxdata.com/t/calculation-of-energy-counter-data/9445>\
**Category:** Fluxlang\
**Created:** [April 15, 2019, 7:26pm UTC](https://community.influxdata.com/t/calculation-of-energy-counter-data/9445 "2019-04-15T19:26:15Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Tonny](https://avatars.discourse-cdn.com/v4/letter/t/a88e4f/32.png) [@Tonny](https://community.influxdata.com/u/Tonny)\
**Post date:** [April 15, 2019, 7:26pm UTC](https://community.influxdata.com/t/calculation-of-energy-counter-data/9445/1 "2019-04-15T19:26:15Z")

</div>

Hi, I’m very new to influxdb.  
I already managed to log the following energy-counters.

The data is something like this:  
2019-04-15 12:00:00 c1 100  
2019-04-15 12:00:00 c2 1000  
2019-04-15 12:00:02 c1 101  
2019-04-15 12:00:03 c2 1001  
2019-04-15 12:00:03 c1 102  
2019-04-15 12:00:04 c2 1002  
…  
2019-04-15 12:59:59 c1 110  
2019-04-15 12:59:59 c2 1100

Now I want to calculate the total amount of consumed energy for per hour which is the sum of the difference of c1 and the difference of c2

(110-100) + (1100-1000) = 110 kWh

Is it possible with a influxdb query, or do where do I need Kapacitor?

Can you give me hints where to start?

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<div class="post-metadata">

**Author:** ![Anaisdg](https://sea1.discourse-cdn.com/flex023/user_avatar/community.influxdata.com/anaisdg/32/6401_2.png) [@Anaisdg](https://community.influxdata.com/u/Anaisdg)\
**Post date:** [April 16, 2019, 3:04pm UTC](https://community.influxdata.com/t/calculation-of-energy-counter-data/9445/2 "2019-04-16T15:04:58Z")

</div>

Hello @Tonny,  
What does the line protocol look like? Is your data in different measurements? or are c1 and c2 tags? If you’re looking to perform math across measurements I recommend looking at [this blog](https://www.influxdata.com/blog/influxdb-how-to-do-joins-math-across-measurements/) and [this blog](https://dzone.com/articles/practical-uses-of-cross-measurement-math-in-flux).

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<div class="post-metadata">

**Author:** ![Tonny](https://avatars.discourse-cdn.com/v4/letter/t/a88e4f/32.png) [@Tonny](https://community.influxdata.com/u/Tonny)\
**Post date:** [April 17, 2019, 6:15am UTC](https://community.influxdata.com/t/calculation-of-energy-counter-data/9445/3 "2019-04-17T06:15:28Z")

</div>

I come from a SQL world and I’m still stuggeling with the naming concepts.

I’ve only one measurement, and c1 and c2 are tags. In reality there are about 50 counters (C1 … C50).

This is what I have so far.  
SELECT \* FROM (SELECT difference("value") FROM "kWh" WHERE time \> Now() -5m group by "tag") group by "tag"

```auto
name: kWh
tags: tag=C1_Energy
time difference
---- ----------
1555479661000000000 0.25
1555479721000000000 0.1875
1555479781000000000 0.25
1555479841000000000 0.1875

name: kWh
tags: tag=C2_Energy
time difference
---- ----------
1555479661000000000 0.140625
1555479721000000000 0.171875
1555479781000000000 0.09375
1555479841000000000 0.109375

name: kWh
tags: tag=C3_Energy
time difference
---- ----------
1555479661000000000 0.03515625
1555479721000000000 0.03125
1555479781000000000 0.03515625
1555479841000000000 0.03515625
```

I want to know the amount used by every unit (per hour, per day, per week, per month).  
The formula to calculate the used energy for Unit1 = C1 + C2  
The formula to calculate the used energy for Unit2 = C3

Eventually I want to have a table that looks something like this.

```auto
Time Unit1(kWh) Unit2(kWh)
2019-04-15 12:00 0.99 10
2019-04-15 13:00 0.12 5
```

Another option is that everything is stored in the measurement like this  
Time1 C1=123 C2=456 C3=789 … C50 = 321  
This is easier for calculation, but less flexible