Mammoth Forms is a form builder for forms that do maths. Drop fields on a canvas,
write a formula such as {quantity} * {unit_price} + 24%, and the result updates
as the visitor types.

What the free plugin does

Drag & drop builder: palette, canvas with column widths, live settings panel
10 ready-made calculators to start from: renovation quote, cleaning service, website estimate, event & catering, equipment rental, shipping cost, loan repayment, price & discount, BMI and a contact form
Images anywhere in a form, from the media library — and with conditional logic they change with the answers
Tables of your own text, live values and formulas: a price breakdown that updates as the visitor types ({area}, {room:label}, ={qty} * {price})
A “Mammoth Form” block for the block editor, with a live preview, a “Mammoth Form” widget for Elementor — or use the shortcode anywhere
23 field types, including slider, dropdown, radio, checkbox group, date, date and time, number range, country, address, image, table and GDPR consent
Checks of your own on any field: an allowed format (a regular expression, such as two letters and four digits) and a “must be true” rule that reads every answer and result — {end} > {start}, {guests} <= 40, {total} >= 50 — each with your own message, in the browser and again on the server
Save and continue later: a second button keeps the visitor’s answers and gives them a private link (also by email) to finish the form later, on any device
Choices as a list or as buttons
Form styles (Clean, Soft & rounded) with your own colour, corners, size and width — no CSS needed
Links that fill in the form: ?mf_room=Kitchen&mf_area=20
Calculated fields with + - * / ^, parentheses and percentages
Percentages the way a calculator does them: {total} + 24% adds 24% VAT, {price} - 10% takes 10% off
Custom numbers anywhere in a formula: {hours} * 45 + 30
Numbers written the way your visitors read them: 10,000.00, 10.000,00, 10 000,00, 10’000.00, without a thousands separator, or with separators of your own — per form, with a site-wide default that follows your site’s language
Conditional logic — show or hide any field based on the answers above it
Live preview inside the builder, and a test result under every formula
Entries with search, unread / read, stars, notes, editing and bulk actions; export to CSV or JSON with the columns and dates you choose, import from CSV, JSON or NDJSON with column matching — in batches with a progress bar, so tens of thousands of rows import without timeouts
After sending: a message (text or HTML with the visitor’s answers), another page, or any address — and the form can hide itself
A “we received your message” email to the visitor, limited per address so the form cannot be used to send mail to strangers
Admin notification you write yourself: recipients, Bcc, sender, Reply-To, HTML or plain text, {all_fields} or single fields
SMTP: send form emails (or every email of the site) through Gmail, Microsoft 365, your host or any mail service, with a test button; the password is stored encrypted
Emails in the background: the visitor sees the confirmation at once and the emails follow a few seconds later — for the whole site or per form
Spam protection: honeypot, Cloudflare Turnstile, hCaptcha or Google reCAPTCHA v3, Akismet (when the site uses it), and a limit of submissions per visitor per hour; logged-in-only forms
Export forms to a JSON file and import them on this or another site
Every value recalculated on the server, so the stored total cannot be forged

Mammoth Forms Pro

Formula functions: IF, ROUND, CEIL, FLOOR, MIN, MAX, SUM, AVG, ABS, MOD, POW, CLAMP
Price tables — tiered pricing and rate lookups with LOOKUP() and TIER()
Chained calculations: one calculated field feeding another, resolved in order
Forms in steps, with Next / Back and a progress bar
Repeater: rows the visitor adds as needed (rooms, order lines), with a formula per row and column totals
Quote page: each submission gets a private page where the customer accepts the quote with their name and signature, or declines it
More fields: time, stepper (− / +), star rating and file upload; choices as picture cards
Bold and Dark form styles, and the total kept in sight at the bottom of the screen on phones
Calculator insights: views, conversion and where visitors stop, popular choices, a [mammoth_stat] shortcode and live statistics in tables
Result emails to the visitor, with your own template
PDF quote attached to the email
Payments: charge the calculated amount with Stripe or PayPal
WooCommerce: send the calculated total to the cart as a custom-priced product

External services

Mammoth Forms works without any outside service. These optional services can be switched on by the site owner:

Cloudflare Turnstile — when chosen under Mammoth Forms > Settings > Spam protection, pages with a protected form load Cloudflare’s script from challenges.cloudflare.com, and each submission’s check token, together with the visitor’s IP address, is sent to Cloudflare to confirm the visitor is not a bot. Terms, Privacy policy.
hCaptcha (Intuition Machines) — when chosen instead, pages with a protected form load hCaptcha’s script from js.hcaptcha.com, and each submission’s check token, the site key and the visitor’s IP address are sent to api.hcaptcha.com to confirm the visitor is not a bot. Terms, Privacy policy.
Akismet (Automattic) — only when the Akismet Anti-spam plugin is active and connected, and “Check every submission with Akismet” is ticked under Settings > Spam protection. Each valid submission’s first name and email answers, its text answers, the visitor’s IP address, browser and the page address are then sent through the Akismet plugin to Akismet to check for spam. Terms, Privacy policy.
Google reCAPTCHA v3 — when chosen instead, pages with a protected form load Google’s script from www.google.com, which assesses the visit, and each submission’s token and the visitor’s IP address are sent to Google for a score. Terms, Privacy policy.

Email is sent through your own server, or — only if you enter one under Settings > Email (SMTP) — through that SMTP server (for example Gmail, Microsoft 365 or your host). The plugin then connects to the address you entered and sends it the messages (recipients, subject, content) and the user name and password you gave it; nothing goes anywhere else. That provider’s own terms and privacy policy apply.