How it's worked out
Pipeline coverage ratio = open pipeline value for the period / target still to close in the period. Count only opportunities expected to close in the period, and take what you've already closed off the target first.
How much coverage you need comes from your own win rate by value. At 25%, each dollar of pipeline turns into 25 cents, so you need 4x. At 33% you need about 3x, and at 20% you need 5x. It's 1 divided by your win rate, which is why one team's healthy ratio is another team's shortfall.
Worked example, with made-up figures: your quarter's target is $150,000 and you've closed nothing yet. You have $360,000 in the pipeline, so 2.4x. Your win rate by value is 25%, so you need 4x, which is $600,000. You're $240,000 short. At a $5,000 average deal that's 48 more opportunities, and with 12 weeks left, 4 new ones a week.
Coverage can also look better than it is. A pipeline full of deals nobody has touched in a month can read 6x and close like 2x. Clear out the stale deals before you trust the ratio.
Where it shows up in your week
Low coverage is fixed with new opportunities, and those come from calls and meetings. The activity calculator works back from your target to the calls, conversations and meetings each week needs, from your own conversion rates. The pipeline management guide shows the gap for next month, worked out step by step, and the pipeline value calculator adds up the open and the weighted pipeline to divide by your target.