A sales funnel calculator models the progression of prospects through each stage of your pipeline — from raw leads to closed customers — so you can project revenue and identify the weakest stage.
Standard B2B Funnel Stages
Stage
Typical Conversion Rate
Lead → MQL
20–40%
MQL → SQL
30–50%
SQL → Opportunity
40–60%
Opportunity → Close
20–30%
Overall Lead → Customer
1–5%
Overall Funnel Conversion
Overall Conversion = New Customers / Leads × 100
An overall conversion rate of 1–3% is typical for B2B SaaS. Above 5% is excellent and usually indicates strong brand/inbound signals.
Finding Your Bottleneck
The stage with the lowest conversion rate relative to benchmark is your constraint. Doubling your lead volume with a broken MQL→SQL stage produces the same number of customers — just twice the waste.
Revenue from the Funnel
Monthly Revenue = New Customers × ACV
Model multiple scenarios: optimistic (improve one stage by 10%), base, and pessimistic (leads drop 20%) to stress-test your pipeline.
A sales funnel is a model that maps how prospects move from initial awareness through to a closed sale, with each stage converting a percentage of the previous stage into the next.
A sales funnel (also called a revenue funnel or pipeline) maps the journey from raw lead to paying customer. The "funnel" shape reflects the reality that only a fraction of prospects at each stage advance to the next.
Standard B2B Funnel Stages
Lead → MQL → SQL → Opportunity → Customer
Lead: Any contact who has shown initial interest (downloaded content, attended a webinar, filled out a form).
MQL (Marketing Qualified Lead): A lead scoring threshold has been met — demographic fit, intent signals, or engagement level.
SQL (Sales Qualified Lead): Sales has reviewed the MQL and confirmed it is worth pursuing (BANT criteria: Budget, Authority, Need, Timeline).
Opportunity: A formal deal has been opened in the CRM with an identified budget and a defined decision timeline.
Customer: The opportunity is closed-won and revenue is recognised.
Why Funnel Modelling Matters
Funnel modelling lets you work backwards from a revenue target to the number of leads you need. If you need 10 new customers per month and your end-to-end conversion is 2%, you need 500 leads. If you can only generate 300, you either need to improve conversion or find more lead sources.
Common Funnel Mistakes
Optimising the top when the bottom is broken — Doubling leads with a 10% close rate produces the same revenue as 500 leads with a 20% close rate.
Misaligned MQL definitions — Marketing and sales disagreeing on what qualifies as an MQL inflates MQL counts while SQL rates collapse.
Ignoring cycle time — A fast funnel (15-day sales cycle) compounds faster than a slow one (90-day cycle) even if conversion rates are equal.
An MQL (Marketing Qualified Lead) meets marketing's engagement criteria. An SQL (Sales Qualified Lead) has been reviewed by sales and confirmed as a viable, near-term deal opportunity.
The MQL-to-SQL handoff is one of the most important — and most contentious — processes in B2B revenue operations. Misalignment here is a top driver of poor funnel conversion and sales-marketing friction.
MQL Definition
A Marketing Qualified Lead is a prospect who has engaged enough with your content or product that marketing deems them worth pursuing. Typical MQL criteria:
Job title matches your Ideal Customer Profile (ICP)
Company size within target range
Has requested a demo, downloaded a high-intent asset, or crossed a lead score threshold
SQL Definition
A Sales Qualified Lead is an MQL that a sales rep has reviewed and confirmed meets BANT (or MEDDIC) criteria:
Budget: Sufficient budget exists or can be allocated
Authority: The contact has or influences the buying decision
Need: A genuine business problem that your product solves
Timeline: An actionable timeframe within your selling cycle
MQL→SQL Conversion Benchmark
Industry median MQL-to-SQL conversion is 20–40%. Below 20% signals over-permissive MQL criteria (marketing qualifying too broadly). Above 50% can indicate under-permissive criteria (leaving valid leads in marketing nurture too long).
Improving the Handoff
Define MQL criteria in a joint marketing-sales SLA. Review the conversion rate monthly. When rates drop, audit rejected MQLs to recalibrate scoring — not just chase more volume.