How to use
Turn email campaign assumptions into projected clicks, purchases, revenue, profit and ROI. Compare transparent scenarios and estimate the list size needed for a revenue goal.
Use ROI Calculator to enter six primary assumptions: list size, delivery rate, open rate, click-through rate, purchase conversion and average sale. Campaign cost is under Advanced and defaults to $500. USD, EUR and GBP change formatting only, without exchange-rate conversion. Reveal Scenario assumptions to edit conservative and optimistic rate changes. Revenue Goal estimates a required audience; Benchmarks offers dated reference starting points.
Results update locally. Copy Result and Copy scenarios produce plain text; if clipboard access fails, selectable copy text appears. Reset restores the documented fixture, USD, a $10,000 goal, scenario defaults and ROI Calculator mode. Refresh clears edits. Interactive controls require JavaScript; the explanations below do not.
Email funnel model
The revenue branch is Sent → Delivered → Clicks → Expected purchases → Projected revenue. Opens branch separately from delivered emails as a diagnostic stage. CTR is based on delivered emails, so opens are not multiplied into clicks. This is a mathematical projection from your rates, not an observed campaign outcome.
Expected purchases can be fractional: 29.4 represents a rate-based expectation across many recipients, not a literal fraction of a person. Downstream revenue retains that unrounded expected value.
Delivery rate
Delivery rate = Delivered / Sent × 100. Delivered = List size × (Delivery rate / 100). Not delivered = Sent − Delivered. In the default fixture, 25,000 × 98% = 24,500 delivered emails and 500 not delivered. “Delivered” does not prove inbox placement or that a recipient read the email.
Open rate
Open rate = Unique tracked opens / Delivered × 100. Estimated opens = Delivered × (Open rate / 100). Here, 24,500 × 35% = 8,575. Tracking commonly depends on remote images; different platforms may report opens differently. Treat the open stage as context for engagement, subject to measurement limitations.
Click-through rate
Click-through rate (CTR) = Unique clicks / Delivered emails × 100. Estimated clicks = Delivered × (CTR / 100). 24,500 × 3% = 735 clicks. Do not calculate clicks as 8,575 opens × 3%; that would use a click-to-open denominator instead.
Click-to-open rate (CTOR) = Unique clicks / Unique tracked opens × 100. With CTOR, opens would feed clicks, but this version uses CTR only. Repeated clicks by one recipient are not additional unique recipients.
Purchase conversion
Purchase conversion rate = Purchases / Clicks × 100. Expected purchases = Clicks × (Purchase conversion rate / 100). The default gives 735 × 4% = 29.4 expected purchases. Use a compatible denominator and attribution window; a platform’s conversions per sent email or per delivered email are different inputs.
Purchase conversion depends heavily on offer, business model, attribution window, and measurement definition. No universal purchase-conversion benchmark is supplied here.
Revenue, profit and ROI
Revenue = Expected purchases × Average sale value. Profit = Revenue − Campaign cost. ROI = ((Revenue − Campaign cost) / Campaign cost) × 100. Rates are entered as percentages and divided by 100 for multiplication.
Projected profit only subtracts the cost you enter. Include production, platform, fulfillment or other costs in your campaign cost if you want them represented. This is not automatically gross margin, lifetime value, tax-adjusted profit or measured attribution. At zero cost, profit equals revenue and ROI percentage is undefined.
For a paid-acquisition question, compare an independent paid-traffic break-even model with explicit order costs. Email opens, delivered-message clicks and paid ad clicks have different denominators; neither tool automatically includes costs entered only in the other.
For product-pricing context, check markup and gross margin definitions separately. This campaign model subtracts only entered campaign cost; product gross margin, contribution after variable costs and campaign profit are not interchangeable. Reconcile relevant costs once.
To examine value beyond this campaign’s purchases, compare a separate customer lifetime-value model with independently chosen lifetime and margin assumptions. Campaign revenue, gross-profit LTV and attributed profit are different measures; do not add them together.
Scenario projections
Expected uses your entered rates. Conservative defaults subtract 5 percentage points from open rate, 1 from CTR and 1 from purchase conversion; Optimistic adds the same amounts. These are editable scenario assumptions, not industry truth or predicted performance. Adjusted rates are capped at 0–100% and the table shows the actual rates used.
Delivery, list size, average sale and campaign cost stay fixed across scenarios. Each scenario recomputes delivered, opens, clicks, purchases, revenue, profit and ROI using the same formulas.
Impact analysis
“What moves the projection?” shows the revenue difference from +1 percentage point delivery, +1 percentage point CTR, +1 percentage point purchase conversion and +1 unit of the selected currency in average sale value, holding every other input fixed. At a boundary the increase is capped and labeled. This is mathematical sensitivity, not a causal claim or strategic ranking.
Open rate changes estimated opens, but does not directly change projected revenue in this model because click-through rate is entered separately as a percentage of delivered emails.
You can compare changes in campaign outcomes using matching campaign periods and metric definitions. Distinguish relative revenue changes from percentage-point changes in funnel rates; neither comparison proves causation.
Revenue goal planning
Required delivered emails = Revenue goal / (CTR × Purchase conversion × Average sale value). Required sent/list size = Required delivered / Delivery rate. In these reverse formulas, rates are decimal fractions, such as 0.03 for 3%.
Show the exact mathematical requirement, then ceiling(exact result) for the minimum whole-number list size. Project expected delivered, opens, clicks, purchases and revenue from that whole-number list. Open rate remains diagnostic under Advanced and does not affect the list requirement. A positive goal requires positive delivery, CTR, purchase conversion and sale value.
Email benchmarks
The current reference snapshot is Mailchimp’s Email Marketing Benchmarks & Industry Statistics (opens in a new tab), last updated December 2023 and reviewed October 2, 2026. These are historical averages, not fresh forecasts. The public dataset covers campaigns sent to at least 1,000 subscribers.
- Ecommerce: tracked open rate 29.81%; delivered-email CTR 1.74%.
- Other / All Users: tracked open rate 35.63%; delivered-email CTR 2.62%.
Use benchmark fills only those two editable assumptions. Purchase conversion remains user-supplied. Other industry presets are omitted when comparable sourced values are unavailable.
Benchmarks vary by industry, audience, geography, sender reputation, message type, list quality, measurement methodology, privacy protections and platform reporting conventions. Reporting denominators may differ across platforms. Use references as starting points, not performance guarantees.
Open-rate measurement limitations
Apple Mail Privacy Protection (opens in a new tab) downloads remote content in the background, independently of whether someone engages with the message. Image preloading can inflate or otherwise distort pixel-based tracked opens. Opens remain a contextual signal; clicks and downstream conversions often provide stronger behavioral evidence. Automated link checks can also affect click reporting.
The calculator does not identify human opens, filter bots or reconcile platform reporting. Choose compatible rate definitions and a consistent observation window before comparing campaigns.
Worked examples
1. Default campaign projection
- Delivered: 25,000 × 98% = 24,500
- Estimated opens (diagnostic): 24,500 × 35% = 8,575
- Estimated clicks: 24,500 delivered × 3% CTR = 735
- Expected purchases: 735 × 4% = 29.4
- Revenue: 29.4 × $120.00 = $3,528.00
- Profit: $3,528.00 − $500.00 = $3,028.00
- ROI: $3,028.00 / $500.00 × 100 = 605.6%
Using 29 instead of 29.4 would incorrectly reduce revenue to $3,480.00. The calculator keeps the expected value unrounded internally.
2. Zero campaign cost
With the same rates and $0 cost, projected revenue is $3,528.00 and projected profit is $3,528.00. ROI percentage is undefined because its denominator is zero. Revenue and profit remain available.
3. A $10,000 revenue goal
At 98% delivery, 3% CTR, 4% purchase conversion and $120 average sale, the required delivered audience is 69,444.444. Exact sent requirement: 70,861.678. Minimum whole-number estimated list size: 70,862.
From that list: 69,444.76 expected delivered, 24,305.666 expected opens at 35%, 2,083.343 clicks, 83.334 expected purchases and $10,000.05 projected revenue. Display rounding does not change the reverse calculation.
4. Open rate changes while CTR stays fixed
Changing open rate from 35% to 45% gives 11,025 estimated opens instead of 8,575. Clicks remain 735, revenue remains $3,528.00 and ROI remains 605.6%, because delivered-email CTR is still 3%.
Assumptions and limitations
These are mathematical projections based on the assumptions entered, not guaranteed campaign outcomes. The calculator estimates revenue; it does not determine whether purchases were caused by an email. Projected revenue is not measured attribution.
Rates are independent inputs. A click count above tracked opens can reflect measurement differences and is not silently constrained. Constant rates, one average sale value and a single campaign cost simplify audience behavior; refunds, repeat purchases, uncertainty and unentered expenses are not separately modeled.
Bounds: list size 0–1 billion; money 0–1 trillion; rates 0–100%; scenario changes −100 to +100 percentage points with direction constraints. Values must be finite plain decimals. Goal requirements exceeding 1 billion recipients are reported as unsupported. All entered values stay in page memory; no accounts, persistent campaign data, URL serialization or network calculations are used.
FAQ
How do I calculate email campaign ROI?
Subtract campaign cost from projected revenue, divide that projected profit by campaign cost, and multiply by 100. If campaign cost is zero, the ROI percentage is undefined; revenue and profit are still shown.
How is email revenue projected?
Multiply sent list size by delivery rate, CTR, purchase conversion rate and average sale value. Use rates as decimal fractions. Keep expected purchases unrounded until after revenue is calculated.
What is email open rate?
Here, open rate is unique tracked opens divided by delivered emails, times 100. Image loading and privacy protections can make tracked opens differ from human engagement. Platform reporting definitions may vary.
What is click-through rate?
Click-through rate (CTR) is unique clicks divided by delivered emails, times 100. Count a recipient once rather than counting every repeated link click.
Is CTR calculated from delivered emails or opens?
This calculator uses delivered emails as the CTR denominator. A percentage of opens would be click-to-open rate (CTOR), which is not an input in this version.
Why doesn’t open rate directly change revenue in this calculator?
CTR is entered independently as a percentage of delivered emails. Open rate only changes estimated opens. Multiplying opens by this CTR would double-count an engagement stage and use the wrong denominator.
What is the difference between CTR and click-to-open rate?
CTR divides unique clicks by delivered emails; CTOR divides unique clicks by unique tracked opens. A 3% CTR cannot be used as a 3% CTOR. This version supports CTR only.
How do benchmark presets work?
Use benchmark fills only open rate and CTR from a dated, sourced reference. All inputs remain editable. Delivery rate, purchase conversion, sale value and campaign cost remain your assumptions.
Why can email open rates be unreliable?
Privacy-related image preloading can register a tracked open without a person reading the message. Open data can still provide context, but clicks and downstream conversions often provide stronger behavioral signals. Automated clicks and reporting conventions also need consideration.
How do I estimate the list size needed for a revenue goal?
Divide the positive goal by CTR × purchase conversion × average sale value to find required delivered emails, then divide by delivery rate. Round the exact sent requirement upward to a whole recipient. Every multiplier must be positive.
Sources
Sources and benchmark data reviewed October 2, 2026. Mailchimp’s public benchmark snapshot is dated December 2023; living metric documentation has no publication date claimed here. Sources explain reporting and privacy; they do not endorse BuzCalculator. Product bounds, scenario defaults and reverse planning conventions are ours.