How do you measure the area under a line graph?


In my case, I am curious to work out my daily kW/h spend. Week and month totals would be interesting too. How do I achieve that?

Guess best experience on second thought would be to make a range selection and get a total spend for that!


You need to calculate integral. Check used TSDB doc, some TSDB (InfluxDB) supports Integral function out of the box.


Your graph is labelled as kWh so is already energy and not power. Your would integrate energy in kW to power in kWh using a simple integral function in InfluxDB/Grafana.
I have a meter providing kW and run :

FROM default PLC1 WHERE Instrument_ID = 301176
SELECT field (Value) integral () math ( / 3600)
GROUP BY time (1s)
FORMAT AS Time series

I do this in a SingleStat box as I am only after the single accumulated kWh over the entire time range selected