Sales Forecasting Calculator
Enter your open deals by stage with the probability you actually believe. Get the weighted forecast, the commit and best case, the gap against quota, and whether your coverage clears 3x.
The number you are called on
New business quota for the period you are forecasting. Keep the pipeline below on the same period.
Open pipeline by stage
Count and total value of every open deal at each stage. Default probabilities are typical B2B figures: override them with your own closed-won history, which is the only source that matters.
Where the weighted forecast comes from
Each stage value multiplied by its probability. These five bars add up to the weighted forecast.
Coverage
Total open pipeline divided by quota. The usual benchmark is 3x.
Read on the forecast
The weighted forecast clears quota by $6,000. Do not call that as your commit: check the commit case, $570,000 of deals at 70% or above, against the $1,200,000 quota. Weighted numbers only work as an average across many deals, and if your stage probabilities are ten points optimistic this surplus is already gone.
How this works
How the weighted forecast is built
Multiply the total value of each stage by that stage probability, then add the results. A stage holding 720,000 at 50% contributes 360,000. Commit and best case are calculated differently on purpose: they are the full, unweighted value of everything above a probability threshold, 70% for commit and 40% for best case. That matches how a forecast call works. You do not commit three quarters of a deal, you either call it for the quarter or you do not.
Your stage probabilities are probably wrong
The defaults here (10, 25, 50, 75, 90) are the common B2B pattern, and they are a placeholder until you replace them. Take every deal that entered each stage over the last four quarters and divide the ones that closed won by the total. That is your real probability. Most teams discover their proposal stage converts at 35% rather than 50%, which means the forecast they have been calling has been roughly 30% optimistic for years, and nobody found it because the miss always got blamed on individual deals.
What the 3x coverage rule really means
Three times quota in open pipeline is the standard benchmark because it assumes roughly a 33% win rate. If your win rate is 20%, your rule is 5x, not 3x. The number is derived, not handed down. And coverage above 4x is rarely good news: it usually means the pipeline is padded with deals nobody has touched in six weeks. Purge anything without a booked next step before you trust the ratio, because an inflated denominator is a very comfortable way to hide a real gap.
Weighted forecast versus the number you commit to
Never call the weighted forecast as your commit. Weighted is a statistical expectation across many deals: it is useful in aggregate and meaningless for any single deal, none of which will close at 50%. Commit is the list of deals you would personally bet on, and it should be shorter than the weighted number suggests. When commit and weighted diverge badly, that is a signal about stage hygiene, not about the maths.