Pro: bulk rows and an API
The same signed-off formulas, run across a CSV of SKUs. Pro is £19 a month or £190 a year, with 500 API calls a month. Pro Plus is £49 a month or £490 a year, with 10,000 calls and a branded calculator embed.
Subscribe
Pro
£19.00 / month
- Bulk CSV of freight class and dimensional weight
- 500 API calls per calendar month
- One call can include up to 500 SKU rows
Pro Plus
£49.00 / month
- Everything in Pro
- 10,000 API calls per calendar month
- Branded freight class embed for your site
Bulk CSV
Columns: sku, unit_system, length, width, height, weight, quantity. Up to five rows run in the browser. Larger files use the API key from your subscription email. Formula version 2025-10-16.1.
API access
A subscription emails an fm_… key once. Send it as Authorization: Bearer to POST /api/v1/calculate. Pro allows 500 calls per calendar month. Pro Plus allows 10,000. Each request is one call, with up to 500 rows. Operator keys created with the ops key are not counted.
curl -X POST $SITE/api/v1/calculate \
-H "Authorization: Bearer fm_…" \
-H "Content-Type: application/json" \
-d '{"rows":[{"sku":"PAL-1","unitSystem":"imperial","length":48,"width":40,"height":48,"weight":500,"quantity":1}]}'Branded embed
The freight class calculator can be embedded without a plan. Pro Plus adds your company name and colour. The frame still links to FreightMath.
Paste a Pro Plus key and choose Check key to edit the brand.