How to find total number of steps per month/year
How do you see the total number of steps per month or year on Apple Watch or iPhone in 2021?
I had this question and finally found out the answer. You don't have to use a third party app. (Note: I have not found a way to see these stats on the watch, but they are available on your phone, and it should be the exact same step count if your Apple Watch is syncing to your iPhone.) Open the Health app on your iPhone. Under Summary, click on your Steps. At the top, tap M (for month) or Y (for year). If you want the total for a specific month, touch the graph and scroll left or right until only that month is showing (see image). Annoyingly, Apple only shows you the average daily steps for that month, but this is still useful, because you can just reverse their math. Multiply the average daily steps by the number of days in the month. (Ex. my average daily steps for June 2021 is 6,968. There are 30 days in June. So 6,969 x 30 = 209,040 total steps for June.)
The same can be done for total steps in a year. Tap the Y, take the average daily steps number and multiply it times 365 (or 366 for a leap year).
If you would like to use a third party app, I've found StepsApp to be useful. Open the app, tap Steps at the bottom center. Tap Month at the top. Swipe sideways to the month you need, and the total month's steps will be displayed at the top (see image).
Apple Watch SE, watchOS 7