Why Use the CalculateCBM API?
Building a CBM calculator from scratch takes 3–5 developer days. The API takes 30 minutes to integrate.
Sub-100ms Response Time
Every endpoint responds in under 100 milliseconds. Suitable for real-time quoting screens, checkout flows, and user-facing calculators where latency is visible.
IATA-Standard Divisors
Volumetric weight calculations use the same 6,000 cm³/kg divisor that airlines and freight carriers use. Your quotes match what carriers invoice — no reconciliation surprises.
$99/yr vs 3–5 Dev Days
At a $150/hr dev rate, building a CBM calculator in-house costs $2,000–$4,000 in development time alone — before ongoing maintenance. The API costs $99/yr. It pays for itself in the first hour you don't spend on it.
What the API Returns
One POST to /calculate returns everything you need for any freight quoting workflow:
POST https://api.calculatecbm.com/v1/calculate
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json
{
"items": [
{ "description": "Carton A", "length": 60, "width": 40, "height": 50, "unit": "cm", "quantity": 20, "weight_kg": 15 },
{ "description": "Carton B", "length": 80, "width": 60, "height": 60, "unit": "cm", "quantity": 10, "weight_kg": 25 }
]
}
// Response (sub-100ms):
{
"success": true,
"items": [
{
"description": "Carton A",
"cbm_unit": 0.12,
"total_cbm": 2.4,
"total_cft": 84.74,
"vol_weight_sea_kg": 2400,
"vol_weight_air_kg": 8000
},
{
"description": "Carton B",
"cbm_unit": 0.288,
"total_cbm": 2.88,
"total_cft": 101.7,
"vol_weight_sea_kg": 2880,
"vol_weight_air_kg": 9600
}
],
"totals": {
"cbm": 5.28,
"cft": 186.44,
"weight_kg": 550,
"vol_weight_sea_kg": 5280,
"vol_weight_air_kg": 17600,
"chargeable_weight_sea_kg": 5280,
"chargeable_weight_air_kg": 17600,
"fit_20gp": 6,
"fit_40gp": 12,
"fit_40hc": 14
}
}Endpoints
| Method | Endpoint | What it does |
|---|---|---|
POST | /v1/calculate | CBM, CFT, litres, volumetric weight (air + sea), container fit for one or many items |
POST | /v1/volumetric-weight | Chargeable weight only — actual vs volumetric, returns the higher value |
POST | /v1/container-fit | How many cartons fit in a 20GP, 40GP, or 40HC container |
POST | /v1/convert | Unit conversion: mm/cm/m/in/ft, kg/lb, CBM/CFT/litres |
GET | /v1/status | API health check, your current request quota, and reset time |
Full endpoint documentation with request schemas and error codes →
Who Uses the CalculateCBM API?
The API is designed for engineering teams building logistics and e-commerce software who need freight calculations without owning the math.
| Platform Type | How They Use It | Key Endpoints |
|---|---|---|
| WMS / Warehouse Systems | Auto-calculate CBM from inbound packing lists at goods receipt | /calculate |
| TMS / Freight Platforms | Instant quoting — CBM + chargeable weight from shipment data | /calculate, /volumetric-weight |
| Freight Forwarder Portals | Real-time CBM and container fit on quote requests | /calculate, /container-fit |
| E-commerce Checkout | Volumetric weight at checkout to select correct shipping tier | /volumetric-weight |
| 3PL Billing Systems | Automated billable weight calculation for storage and fulfillment invoicing | /calculate, /volumetric-weight |
Pricing
Two plans. No per-call fees. No setup fees. Cancel anytime.
Full plan comparison at /api/pricing
Quick Start — 3 Steps to Your First Response
From zero to a working API call in under 30 minutes.
Choose a plan on the pricing page, complete checkout, and your API key is emailed instantly. No sales call, no approval process.
POST a JSON payload with your item dimensions. Works with any language — curl, Python, Node.js, PHP, Java, .NET, Go.
The JSON response contains everything: CBM, CFT, litres, volumetric weight for air and sea, and container fit counts. Plug the values directly into your UI.
Example curl call:
curl -X POST https://api.calculatecbm.com/v1/calculate \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"items": [
{
"description": "Carton",
"length": 60,
"width": 40,
"height": 50,
"unit": "cm",
"quantity": 10,
"weight_kg": 12
}
]
}'Frequently Asked Questions
429 Too Many Requests status once your daily limit is reached. Limits reset at midnight UTC. You'll receive an email at 80% and 100% usage. Upgrade to Enterprise if 1,000 requests/day is insufficient — or contact us for custom volume pricing.Ready to integrate in 30 minutes?
Read the docs, pick a plan, get your key. No sales process.