The short answer
- For 5,000 subscribers, one monthly campaign and two automated emails per new signup, estimate 5,000 + 2N marketing sends, where N is the number of new signups receiving both messages. Add tests, other campaigns and applicable transactional messages before choosing an allowance.
- Mailchimp selects a contact tier and applies a plan-specific send multiple; Brevo's documented paid tiers pair a monthly send allowance with a storage limit. The smallest Brevo Starter or Standard tier that can store 5,000 contacts currently allows 20,000 monthly sends.
- There is no reliable price winner from advertised starting prices: request or calculate current prices for the same audience, features, billing term and message volume.
The same workload for both
Imagine a small business with 5,000 subscribed contacts. It sends one campaign to all 5,000 each month and a two-message welcome sequence to N new signups. If every signup receives both messages in that month, the planned marketing volume is 5,000 + 2N recipient sends. This is a planning assumption, not a forecast; messages delayed into another month, suppressions and additional sends change the count.
The 5,000 are subscribed contacts, not necessarily the entire database. Add unsubscribed, non-subscribed and other retained records as each vendor counts them; allow for growth and make sure your sending permissions are valid. Neither the number of signups nor a total quote is assumed here.
Count the contacts and sends
On a monthly paid Mailchimp plan, choose a plan and maximum contact count across audiences. Subscribed, unsubscribed and non-subscribed records count; archived, cleaned and deleted contacts do not count toward the marketing plan according to its definitions. The plan comparison lists monthly sends of 10 times the contact tier on Essentials, 12 times on Standard and 15 times on Premium. Check the current selected tier and whether extra records or repeated audience entries change the count. Mailchimp notes that paid plans created before May 15, 2019 may follow different contact-limit rules; verify legacy terms.
Brevo's plan documentation pairs the 5,000, 10,000 and 15,000 monthly-send tiers with storage limits of 500, 1,500 and 2,500 contacts respectively. Its Starter and Standard tables give up to 500,000 stored contacts starting at the 20,000-send tier. For this scenario, that is the first documented paid tier that holds 5,000 contacts; choose more sending capacity if 5,000 + 2N plus other messages requires it.
Compare actual quotes rather than the vendors' smallest advertised entry prices. Record the contact count, monthly sends, automation tier, seats, billing period, renewal price, taxes and add-ons. Plans and promotional terms can change. Brevo's starting price is for its first tier, not a quote for 5,000 stored contacts.
Test the welcome sequence
Mailchimp's plan comparison lists up to four flow steps on Essentials, while its classic automation migration guide says three. Standard and Premium list up to 200 flows. These sources use different limits and disagree on Essentials; confirm the current entitlement and map the trigger, waits, messages and conditions to the current builder before choosing.
Brevo lists marketing automation for up to 2,000 contacts on Free and lists unlimited-contact marketing automation on Standard; Starter includes the Free features. Confirm how the applicable contact limit is counted and whether the welcome flow and its monthly entry volume fit your chosen plan. A 5,000-person stored audience alone does not establish how many enter the automation.
Before choosing, map the signup event, delays, exclusions, re-entry and unsubscribe behavior. Review with a representative test record and sending paused, and assign someone to maintain the workflow as forms and offers change.
Allow for transactional messages and overruns
A welcome promotion and an order confirmation have different purposes. Mailchimp distinguishes its Marketing system from Mailchimp Transactional, a paid add-on for Standard or Premium monthly Marketing plans that uses recurring blocks. Its transactional pricing page also lists the legacy Monthly Plan and a limited free demo; confirm account eligibility. Marketing also offers limited transactional messages. Its Marketing pricing definitions say test and transactional emails count toward the monthly sending limit; confirm the applicable allowance for your specific sending route.
Brevo lists transactional email on its Free plan and says its prepaid email credits can be used for marketing and transactional email. Paid plan emails are used first, then prepaid credits if available. Include both message types in your capacity estimate and confirm activation and queue behavior for your account.
Mailchimp's terms distinguish paid monthly overage charges from annual-plan sending holds at usage limits. Its Free plan pauses sending when a contact or email-send limit is exceeded. Brevo describes optional prepaid credits that can back up paid plan emails; check current contact-limit and exhaustion rules before relying on automatic continuity. Set a budget owner and agree when to add capacity.
Move permission and suppression with the audience
Mailchimp's contact export may contain separate files for subscribed, unsubscribed, non-subscribed and cleaned contacts. Keep those distinctions and the evidence of permission with the migration inventory. Do not import every row as a marketing subscriber.
Brevo's blocklist guidance distinguishes campaign channels from transactional email. A marketing blocklist is not a substitute for checking transactional sender restrictions. Reconcile each status, map fields, inspect duplicates and validate a small set of synthetic records before enabling a workflow.
When to look beyond these two
Explore ActiveCampaign if more involved workflows or sales handoffs are the primary job. If application events, company relationships or transactional routes drive the decision, the adjacent lifecycle email guide compares Customer.io, Loops and Userlist on those questions.
Read the individual Mailchimp and Brevo profiles for plan and migration details. Neither a plan table nor this comparison replaces a test of your own workflow.
Common questions
Which is cheaper for 5,000 subscribers?
It depends on retained contact states, sends, automation, billing term and add-ons. Get current configured prices; the vendors' entry prices do not establish a 5,000-contact quote.
How many emails does the example need?
The campaign and welcome sequence need 5,000 + 2N recipient sends if N new signups each receive both welcome emails in the same month. Add other messages and adjust for real timing and suppression.
Does Brevo's 5,000-send tier hold 5,000 contacts?
Its documented Starter and Standard tables pair that tier with up to 500 stored contacts. The tables show up to 500,000 stored contacts from 20,000 monthly sends; verify current terms.
Sources and scope
We read the linked vendor documentation and pricing on November 5, 2026; plan terms and prices can change.
We have not used either product or sent email through them. This is a documentation comparison, not a measurement of deliverability or product performance.
Inclusion and corrections are free; sponsorship does not determine our conclusions. Editorial order is independent of paid placements.
Quillwell LLC also builds Adswell, a paid-media product.
Sponsorship does not buy an editorial ranking or a positive review. How we research.
Source references
- Mailchimp: About pricing tiers
Checked 2026-11-05. Monthly plan contact counting and additional contact blocks.
- Mailchimp: Compare marketing plans
Checked 2026-11-05. Plan send multiples and automation limits; prices depend on selection and offers. Free-plan sending pauses when contact or send limits are exceeded.
- Mailchimp: Standard terms of use
Checked 2026-11-05. Monthly and annual paid-plan treatment at usage limits.
- Mailchimp: View or export contacts
Checked 2026-11-05. Export files and contact status categories.
- Mailchimp: About transactional email
Checked 2026-11-05. Marketing and Mailchimp Transactional plan requirements and sending models.
- Brevo: About pricing plans
Checked 2026-11-05. Current documented contact and send tiers and marketing automation allowances.
- Brevo: Customize your plan with add-ons
Checked 2026-11-05. Prepaid credits and their use after monthly plan emails.
- Brevo: Blocklist, unblock, or resubscribe contacts
Checked 2026-11-05. Distinct marketing and transactional preferences and blocklist imports.
- Mailchimp: About pricing plans
Checked 2026-11-05. Contact states and definition of sends.
- Mailchimp: Change a classic automation to a flow
Checked 2026-11-05. Conflicting Essentials flow-step limit in a classic automation migration guide.
- Mailchimp: About your contacts
Checked 2026-11-05. Contact statuses and legacy paid-plan contact-limit exception.
- Mailchimp: Transactional email pricing
Checked 2026-11-05. Standard and Premium, legacy monthly plan eligibility and free demo.