Mailchimp's pricing scales steeply by contact count. Brevo (formerly Sendinblue) prices by email volume instead — a fundamentally different model that can save 50–80% for large lists. But switching has real hidden costs.
Mailchimp charges by contact list size — even for unsubscribed or inactive contacts you can't delete without losing history. A 50,000-contact list on Mailchimp Standard costs ~$350/month. The same sending volume on Brevo's Business plan (300,000 emails/month) costs ~$65/month.
Conservative estimates for a medium e-commerce or SaaS brand with a 40–80k contact list. Adjust everything to your situation.
| Input | Suggested Value | Notes |
|---|---|---|
| Current monthly cost (Mailchimp) | $350 | Standard, ~50k contacts |
| New monthly cost (Brevo) | $65 | Business, 300k sends/month |
| Contract months remaining | 0 | Mailchimp is month-to-month |
| Migration hours | 40 | Templates + automations + integrations + QA |
| Staff hourly rate | $55 | Marketing manager or email specialist |
| Retraining hours / person | 5 | Brevo platform training |
| Staff needing training | 3 | Email marketing team |
| Downtime hours (total) | 120 | Deliverability warm-up revenue impact |
| Downtime cost / hour | $30 | Conservative revenue-per-send-hour |
| Risk buffer | 15% | Deliverability risk is real and hard to predict |
Opens with the values above pre-filled. Edit any number to match your situation.
Open Calculator with These ValuesAll values are editable. Results are estimates — consult your IT and finance teams.
Export your Mailchimp contacts as CSV (Audience → Export Audience). Clean the list first — remove hard bounces, unsubscribes, and dormant contacts. Import into Brevo via Contacts → Import Contacts, mapping your Mailchimp custom fields to Brevo attributes. Create matching lists and segments. Brevo also has a native Mailchimp importer that handles some of this automatically.
Yes, temporarily. When sending from a new IP or domain, inbox providers haven't seen your sending patterns before. You'll need to warm up gradually — start with 10–20% of your list, focusing on your most engaged subscribers, and scale up over 4–8 weeks. During this time, monitor bounce rates and spam reports carefully. Brevo has a dedicated IP warm-up guide.
Brevo's deliverability is comparable to Mailchimp's for senders with clean lists and good sending practices. Mailchimp has a slight edge in brand recognition with some ISPs due to its scale. However, for most senders, the deliverability difference after a proper warm-up is negligible — and Brevo's transactional email infrastructure is widely considered excellent.