How to Calculate Email Bounce Rate

function calculateEmailMetrics() { var sent = parseFloat(document.getElementById('totalSent').value); var hard = parseFloat(document.getElementById('hardBounces').value) || 0; var soft = parseFloat(document.getElementById('softBounces').value) || 0; var resultDiv = document.getElementById('resultDisplay'); if (!sent || sent <= 0) { resultDiv.style.display = 'block'; resultDiv.style.backgroundColor = '#fff0f0'; resultDiv.style.borderColor = '#f7d0d0'; resultDiv.innerHTML = 'Error: Please enter a valid number for Total Emails Sent.'; return; } var totalBounces = hard + soft; var overallBounceRate = (totalBounces / sent) * 100; var hardRate = (hard / sent) * 100; var softRate = (soft / sent) * 100; var rating = ""; var ratingColor = ""; if (overallBounceRate <= 2) { rating = "Excellent (Healthy List)"; ratingColor = "#27ae60"; } else if (overallBounceRate <= 5) { rating = "Average (Monitor closely)"; ratingColor = "#f39c12"; } else { rating = "High (Risk of Blacklisting)"; ratingColor = "#e74c3c"; } resultDiv.style.display = 'block'; resultDiv.style.backgroundColor = '#f0f7ff'; resultDiv.style.borderColor = '#d0e4f7'; var output = '

Campaign Analysis

'; output += 'Overall Bounce Rate: ' + overallBounceRate.toFixed(2) + '%'; output += 'Status: ' + rating + ''; output += '

---

'; output += 'Total Bounces: ' + totalBounces + ''; output += 'Hard Bounce Rate: ' + hardRate.toFixed(2) + '%'; output += 'Soft Bounce Rate: ' + softRate.toFixed(2) + '%'; resultDiv.innerHTML = output; }

Understanding Your Email Bounce Rate

In email marketing, the bounce rate represents the percentage of email addresses in your subscriber list that didn't receive your message because it was returned by a recipient mail server.

The Formula for Email Bounce Rate

The standard formula used by most Email Service Providers (ESPs) is:

Bounce Rate = (Number of Bounces / Total Emails Sent) x 100

Hard Bounce vs. Soft Bounce

Not all bounces are created equal. It is critical to differentiate between them to maintain a healthy sender reputation:

• Hard Bounce: A permanent reason why an email cannot be delivered. This usually happens when the email address is invalid, non-existent, or the recipient's mail server has completely blocked your domain. You should remove these addresses immediately.
• Soft Bounce: A temporary delivery failure. This occurs when the recipient's inbox is full, the server is down, or the message size is too large. ESPs will typically retry delivery over several days before giving up.

What is a "Good" Email Bounce Rate?

Benchmarking your performance is essential for deliverability. While it varies by industry, here is a general guide:

Bounce Rate	Health Status
Under 2%	Excellent – You have a very clean list.
2% to 5%	Average – Typical for older lists or B2B campaigns.
Over 5%	Poor – High risk of being flagged as spam by ISPs.

Real-World Example Calculation

Suppose you send a newsletter to 5,000 subscribers. After the campaign finishes, your report shows:

• Total Sent: 5,000
• Hard Bounces: 45
• Soft Bounces: 30

First, calculate total bounces: 45 + 30 = 75.

Now, apply the formula: (75 / 5,000) x 100 = 1.5%.

In this scenario, your bounce rate is 1.5%, which is well within the healthy range for a marketing campaign.

How to Lower Your Bounce Rate

1. Use Double Opt-In: Ensure users verify their email address before being added to your list.
2. Regular List Cleaning: Remove inactive subscribers and known hard bounces every 3-6 months.
3. Don't Buy Lists: Purchased lists are notorious for high hard bounce rates and spam traps.
4. Monitor Deliverability: Check if your domain or IP address has been blacklisted using tools like MXToolbox.