Mailchimp, Klaviyo or Brevo: the one number that decides which is cheapest

Comparing the headline plans of Mailchimp, Klaviyo and Brevo is misleading, because the three do not price the same way. Mailchimp and Klaviyo charge by how many contacts you store. Brevo charges by how many emails you send, with unlimited stored contacts. So the cheapest option flips depending on one number about you, not about them.

The default scenario

Take the calculator default: a 10,000-contact list that gets 40,000 emails a month, which is four sends per contact. Using the linear rates anchored to June 2026 reference points, here is what the three models cost.

• Mailchimp, by contacts: about 100 dollars a month (10,000 contacts at roughly one cent each).
• Klaviyo, by contacts: about 150 dollars a month (the same list at a higher per-contact rate).
• Brevo, by emails sent: about 32 dollars a month (40,000 sends at roughly 0.80 dollars per 1,000).

These are planning numbers from a deliberately simple linear model, not quotes. Real plans are tiered step functions, so confirm your own current tier from each provider before you commit. The point is the shape, not the cents.

The number that actually decides it

It is your contacts-to-sends ratio: how many emails each stored contact receives in a month. With the default rates, Mailchimp and Brevo cost the same at about 12.5 emails per contact per month. Below that you send relatively little to a large stored list, and Brevo is cheaper. Above it you mail the same people often, and the stored-contact fee is spread over so much sending that contact pricing wins. Klaviyo, priced higher per contact, only catches Brevo above roughly 19 emails per contact per month.

The same list, two ways

• A 50,000-contact list mailed once a month (50,000 sends): about 500 dollars on Mailchimp, 750 on Klaviyo, and 40 on Brevo. A big list you mail rarely is the strongest case for send-based pricing.
• A 2,000-contact list mailed 20 times a month (40,000 sends): about 20 dollars on Mailchimp, 30 on Klaviyo, and 32 on Brevo. A small list you mail constantly is where contact-based pricing turns cheaper.

Where Klaviyo still earns its premium

On pure cost Klaviyo is the most expensive of the three in this model, so the honest cost answer is rarely Klaviyo. Its case is not price; it is ecommerce revenue attribution and flows tied to store data. If you are not running that, you are paying for capability you do not use, and the cost math above applies straight.

Run your own ratio

Drop your real list size and monthly send volume into the calculator and it shows which model, and which provider, is cheapest for you, with every rate editable so you can paste in your own current tier. The decision is your ratio; the tool just does the arithmetic.