How to Calculate B2B Cold Email ROI: The Complete Formula

Before buying a B2B database or launching a cold email campaign, calculating expected ROI protects against wasted spend and sets realistic expectations for pipeline. This guide walks through the complete calculation with real numbers.

The Inputs You Need

Six inputs determine cold email campaign ROI: (1) List size — number of contacts in your campaign. (2) Cost per contact — list purchase cost divided by list size. (3) Platform cost — your monthly sending platform cost divided by sends per month. (4) Open rate — expected percentage of delivered emails that are opened. (5) Positive reply rate — expected percentage of total sends that result in an interested reply. (6) Meeting conversion rate — percentage of positive replies that become scheduled meetings. (7) Close rate from meeting — your historical percentage of meetings that become customers. (8) Average deal value — your average contract value. Multiplying through these inputs gives you expected pipeline and expected revenue from the campaign.

The Calculation

Example campaign: 2,000 contacts from a LeadsBlue database ($149 one-time cost = $0.075/contact), Instantly platform ($97/month, 5,000 sends/month capacity → $0.019/send), 22% open rate, 5% positive reply rate, 40% reply-to-meeting conversion, 25% meeting-to-close rate, $15,000 average deal value.

Working through: 2,000 sends × 22% open rate = 440 opens. 2,000 sends × 5% positive reply rate = 100 positive replies. 100 replies × 40% meeting conversion = 40 meetings booked. 40 meetings × 25% close rate = 10 deals. 10 deals × $15,000 ACV = $150,000 in expected revenue.

Campaign cost: $149 (list) + $39 (platform cost pro-rated for 2,000 sends) + 3 hours SDR time at $30/hour = $277. Revenue: $150,000. ROI: ($150,000 - $277) / $277 = 540:1.

This is an optimistic scenario. Conservative scenario (3% reply rate, 30% meeting conversion, 15% close rate): 60 positive replies × 30% = 18 meetings × 15% close = 2.7 deals × $15,000 = $40,500 revenue at $277 cost — still 146:1 ROI. Cold email ROI is high because the marginal cost per campaign is so low relative to deal values in most B2B contexts.

Where the Model Breaks Down

The ROI model fails in four scenarios: (1) Your deal value is too low for cold email to make sense — for products under $500 ACV, the time cost of SDR-driven cold email is disproportionate. Self-serve acquisition is typically better at this price point. (2) Your close rate from meetings is very low — if your meeting-to-close rate is below 10%, the problem is in your sales process, not the data. Buying more lists amplifies a broken sales process. (3) Your list quality is poor — if hard bounces exceed 3%, your actual deliverable list is significantly smaller than the purchased list, and the ROI model needs to be adjusted for the real deliverable count. (4) Your market is too small — if there are only 500 companies in your total addressable market, a 2,000-contact list either contains duplicates, irrelevant contacts, or contacts from adjacent but non-ideal markets.