Use the gadget

Settings explained

Open the gadget menu (…) and choose Edit to change any of these.

Setting	What it does
Title	Shown above the number. Optional, up to 80 characters.
JQL	Which issues count. ORDER BY is ignored. Jira checks the query when you save.
Show	Number, Gauge (needs a target) or Trend. See Targets and zones and Trends and comparisons.
Measure	Number of issues, or the sum of a numeric field (Story Points, estimates, custom number fields). A sum covers up to the first 1,000 issues; the gadget says so when it is capped.
Target, Better when, Amber zone	Optional target, whether higher or lower is better, and how close to the target counts as amber (in percent of the target).
Compare with the previous period	Adds this week vs last week (or month) under the number.
Period by, Step, Periods	Which date splits issues into periods (Created, Resolved or Updated), weeks or months, and how many periods a trend shows (4 to 12).
Refresh	How often the dashboard reloads the gadget: every 15, 30, 60 or 120 minutes.

Settings are saved in the gadget itself, so each gadget on a dashboard can show a different KPI.