Transactions per Second
Each day's transactions over the 86,400 seconds in a day
Short ranges plot one point per block, about one every ten minutes. Longer ranges plot one point per day, computed from every block in that day. How it is computed depends on the chart: some average, some total the day up, some are a ratio of the day's sums, and each chart says which. Either way a brief spike inside a day is smoothed away.
About this metric
Definition
How many transactions per second the chain confirmed. Over the past year that has averaged about six, and a single day has run between three and ten.
Only base-chain transactions are counted, so Lightning payments and transfers inside an exchange are absent: both move value without a block recording each one. The line is a floor on activity rather than a measure of it.
How it is measured
The two arms use different divisors, and that is most of what distinguishes them.
Per block the divisor is the actual gap to the previous block, so a short interval reads high and a long one reads low at an identical underlying rate. The spread this produces is enormous: over the past year the median block reads about 7 per second and the 95th percentile over 100, with the highest at 7,009, where block 949,397 carried 7,009 transactions and was stamped one second after its predecessor. A header timestamp is not a clock reading, as the Block Interval chart sets out, so the extremes here come as much from stamping as from mining.
Daily the divisor is a constant 86,400 seconds, so nothing depends on when blocks arrived within the day: the line is the day's transaction count rescaled.
Measured from my own Bitcoin node. Methodology