Email Marketing for B2B (2026): Mailchimp vs Brevo vs HubSpot — The Per-Recipient Cost Curve Your List Size Puts You On

One list. Three tools. Three different numbers.

Put the same 30,000-person B2B list into Mailchimp, Brevo and HubSpot and it appears in three dashboards under three names: “audience”, “contact”, “marketing contact”. Each name is defined differently, each carries its own cap, and each carries a different price. The dashboard is not the truth; it is the vendor’s opinion of the truth. This piece reconciles the three definitions, prices the same list at four sizes, and dates every number it states — because a pricing page without a date is a rumor.

The workload, before any price. The list is one B2B audience. The send cadence is one email per contact per month — the minimum a list needs to avoid going stale. At size N, the bill covers N sends per month. Four sizes: 1,000 / 5,000 / 25,000 / 100,000 contacts. Vendor figures come from the vendors’ own pricing pages, checked 28 September 2026; where a number comes from a dated third-party capture of a vendor page, the capture’s date sits on the line.

Why “per contact” is a moving trap

The three vendors answer the same question — “what exactly am I paying for?” — with three different nouns.

Mailchimp sells the contact. The stored subscriber is the unit; sends are metered as a multiple of the contact count — the page’s own notation, 10X / 12X / 15X contacts by plan (compare-plans page, 28 September 2026). Grow the list and the send allowance grows with it, but so does the price per tier.

Brevo sells the send. Contacts are stored free — up to 100,000 on the free plan — and the bill tracks emails sent. Pay-as-you-go credits work at one email = one credit, and the credits do not expire (pricing page, 28 September 2026).

HubSpot sells the marketing contact. The CRM stores “contacts” — every record — but the marketing plan is priced on “marketing contacts”, the subset attached to marketing lists and campaigns, plus seats (hubspot.com, 28 September 2026; plan capture of 9 August 2026).

If two tools disagree on the same number, one of them is selling you a feature. The unit each vendor picked decides which part of your operation becomes the line item: Mailchimp charges for the list existing, Brevo for the list being used, HubSpot for the list meeting the CRM. None of the choices is wrong, and all three are published. The reconciliation is the translation job.

The pricing models, side by side (28 September 2026)

The cross-category pattern across thirty pricing pages sits in the head-to-head section — checked the same day. This piece reads the same three marketing pages as bills rather than as patterns, so the table here is a bill, not a feature matrix.

One line carries through everything below: Brevo’s tier prices are slider-rendered on its pricing page — a “per month” with no number next to it. Brevo’s own comparison page (brevo.com/klaviyo, 28 September 2026) is where it publishes static numbers, and that page is the source for the Brevo column of the curve.

The cost curve: one list, four sizes, three bills

The same list, priced across the three vendors at four sizes. The bill is the smallest plan that holds the list and covers N sends per month.

The sourcing, line by line:

• Mailchimp. The $13 / $20 / $350 starts, the $385-at-50,000 and $800-at-100,000 tier caps, and the send multiples come from the vendor’s own pages (28 September 2026). The 1,500 / 5,000 / 25,000 points come from a 18 September 2026 dated capture of the same page’s contact slider. At 100,000 contacts, Standard holds the list with 12X = 1.2m sends/mo included — far past the defined workload — while Premium (15X) prices at $1,025 for the same size in that capture, so the curve keeps Standard, the smaller bill.
• Brevo. All four cells are from Brevo’s own “send one email per month” table on brevo.com/klaviyo (28 September 2026): 250 contacts free, 1,500 → $17, 5,000 / 10,000 / 20,000 → $32, 60,000 → $65. One thousand sends sits under the free allowance (300/day ≈ 9,000/mo). Twenty-five thousand and one hundred thousand land between or above the published points, so the table shows the bracket instead of inventing a midpoint.
• HubSpot. The base prices — $20 / $890 / $3,600 — are verified on hubspot.com on 28 September 2026; the extra-contact bands come from the 9 August 2026 plan capture: Starter at $50 per 1,000 (1k–3k), $45 per 1,000 (3k–5k), $40 per 1,000 (5k+). At 100,000 contacts the Enterprise math works to $4,450 ($3,600 + four blocks at $100 per 10,000 + five blocks at $90 per 10,000); the curve keeps Starter, the smaller number, and leaves the seat and feature differences to the next sections.

That is the artifact: a four-point curve across three billing models, dated, and re-computable from the rate tables when they change. Vendors publish price lists. The curve is what the list costs.

What the free tier actually gives you

Three caps, checked the same day, and the first paid step past each one.

• Mailchimp: 250 contacts, 500 sends/mo (250/day). Past the cap, sending pauses — no overage billing on free (compare-plans page, 28 September 2026). First paid step: Essentials at $13 for 500 contacts and 5,000 sends.
• Brevo: 300 emails/day (about 9,000/mo), with up to 100,000 contacts stored free (pricing page FAQ and the klaviyo page, 28 September 2026). Free-tier automation is capped at 2,000 contacts (September 2026 capture). First paid step: Starter, from 5,000 emails/mo.
• HubSpot: the free Marketing Hub is 100 marketing contacts and 2,000 emails/mo (9 August 2026 capture — single source, flagged as such). First paid step: Starter at $20/mo/seat for 1,000 contacts — currently $10 for new customers, a limited-time promo (hubspot.com, 28 September 2026).

Two findings, dated:

1. The stale number is still circulating. A third-party page checked on 18 September 2026 still lists Mailchimp free at 500 contacts / 1,000 sends. The vendor page says 250 / 500. The cap was cut and the web has not caught up. The primary page wins; both figures are here with their dates.
2. Brevo prices from the paid floor, not the free cap. Its own comparison table lists 1,500 sends/mo at $17 even though 1,500 sits under the ~9,000/mo free allowance. The table is selling the upgrade, not the free tier. If your actual volume is under 9,000/mo, the bill is $0 — and the table is not the bill.

The B2B difference: the feature-to-price line

B2B lists grow slowly. A sales cycle adds contacts over quarters; there is no flash-sale spike. The contact count is therefore rarely the line that moves a renewal — the feature gate is.

• Mailchimp gates workflow depth. Essentials holds automations at 4 flow steps; Standard and Premium carry 200. Generative AI is not included on Free or Essentials and is a no-additional-cost add-on on Standard and Premium (compare-plans page, 28 September 2026). The jump from $26.50 to $45 at the same 1,500-contact tier buys 4 → 200 steps and the AI add-on.
• Brevo gates the test-and-learn layer. Marketing automation, A/B testing, and the single landing page start at Standard, from $18/mo (review, 16 September 2026).
• HubSpot gates the team. Seats scale with the tier — 2 / 3 / 5 across Starter to Enterprise — and Professional carries a $3,000 one-time onboarding fee on top of the monthly (9 August 2026 capture).

Count the add-ons before you count the seats. The feature-to-price line is where B2B email actually gets expensive: not the contact, the workflow, the test, the seat. This is a budget line, not a hobby — and the line you defend at renewal is the one that gated the feature, not the one that stored the list.

The dated watchlist: three steepest segments on the curve

The curve has three segments that re-render first when the rate tables change. They are the ones to re-check at the next plan-page update:

1. Mailchimp Essentials, 5,000 → 50,000 contacts: $75 → $385. A 5.1-fold bill for ten times the list (18 September 2026 capture). The contact meter is the only one of the three that taxes storage alone.
2. HubSpot’s marginal cost per 1,000 extra contacts: $50 at the bottom of the Starter band, falling to $9 at the top of the Enterprise band (10,000–200,000, 9 August 2026 capture). The per-1,000 cost of growth falls as you climb the hub — the same 10,000-contact increase costs about five times more at the bottom of the stack than at the top.
3. The free-tier cliffs: 250 (Mailchimp), 300/day (Brevo), 100 (HubSpot). Three numbers that end free, checked 28 September 2026 — and one of the three still quoted at its old figure on third-party pages.

When Brevo’s block pricing wins — and when HubSpot’s all-in-one bill is lower

“Brevo vs Mailchimp,” reduced to the unit: Brevo’s volume pricing wins whenever the workload is send-light per contact and the list is large. Storage is free to 100,000 contacts, so a 50,000-contact list that sends 2,000 emails a month sits under Brevo’s free allowance while the same list sits at Mailchimp’s $385 Essentials tier cap (Brevo cap: 28 September 2026; Mailchimp tier: 18 September 2026 capture). The curve stays Brevo’s until the feature gate does its work: once 200-step automations or the no-additional-cost AI add-on are in scope, Mailchimp’s Standard becomes the price of admission — $100 at 5,000 contacts against $75 on Essentials, a 25% premium that buys the workflow layer (18 September 2026 capture).

“Is HubSpot worth it in 2026” — the honest answer takes two variables, team size and budget band, and the team has to be one that already runs a HubSpot CRM. At 1,000 contacts the all-in-one is the cheaper line on paper: $20/seat — currently $10 for new customers (28 September 2026) — against $26.50 for the same list on Mailchimp, before anything is counted for the CRM the team is already running. At 5,000 contacts the paper math flips: $200 all-in-one against $75 for the email tool, and “worth it” now rests on what the separately licensed CRM would have cost at all — a free CRM makes the two-vendor bill $75 plus the integration work, and no price table prices integration work. Past 5,000 contacts, the extra-contact bands ($40–50 per 1,000 at the bottom of the stack, 9 August 2026 capture) are the steepest per-1,000 marginal cost in this set, and the math stops being close. That is the whole answer; everything past 10,000 contacts is a seat-and-band conversation, not a pricing-page one.

What your budget line should look like

Monthly, one email per contact per month, checked 28 September 2026:

The budget line is the row that matches your actual list size and cadence — not the “from” price at the top of the page, and not the row the demo used. When the rate tables change — and the churn in this niche says they will — re-render the row, date it, and re-read the line above it.