How do I calculate CBM from inches?

CBM = (L inches × W inches × H inches) ÷ 61,023.7. Example: 24 × 18 × 12 inches = 5,184 ÷ 61,023.7 = 0.0849 CBM. Alternatively, convert each inch dimension to meters by multiplying by 0.0254, then multiply the three meter values.

How many cubic inches in 1 CBM?

1 CBM = 61,023.74 cubic inches. This is because 1 meter = 39.3701 inches, and 39.3701³ ≈ 61,023.74. Multiply CBM by 61,023.74 to convert to cubic inches; divide cubic inches by 61,023.74 to get CBM.

What is 1 inch in meters?

1 inch = 0.0254 meters exactly. To convert inches to meters for CBM calculation, multiply each dimension by 0.0254, then calculate L(m) × W(m) × H(m).

Why is 61,023.7 used in the inches to CBM formula?

The divisor 61,023.7 is the number of cubic inches in 1 cubic meter. It comes from the fact that 1 meter = 39.3701 inches, so 1 m³ = 39.3701³ = 61,023.74 in³. Dividing cubic inches by this number converts to cubic meters (CBM).

Is the CBM formula different for US vs international shipping?

No — CBM is universal for international ocean freight. However, US domestic LTL carriers use cubic feet and freight class rather than CBM. For any international ocean or air shipment, CBM is the standard regardless of whether your dimensions are in inches or centimeters.

How to Calculate CBM in Inches — Formula & Converter

Q: Should I use inches or centimeters for CBM?

Use whatever unit appears on your packing list or supplier documentation. US suppliers typically use inches; Asian and European suppliers use centimeters. Both give identical CBM results when the correct divisor is applied. Our calculator accepts both — select your unit from the dropdown.

The CBM Formula for Inch Measurements

CBM (Cubic Meter) is the universal volume unit in international freight. When your carton dimensions are in inches, you convert to CBM using a single divisor — no need to manually convert each dimension to meters first.

The formula is:

Method 1 — Divide by 61,023.7 (recommended):
CBM = (L" × W" × H") ÷ 61,023.7

Method 2 — Convert each dimension to meters first:
L(m) = L" × 0.0254 | W(m) = W" × 0.0254 | H(m) = H" × 0.0254
CBM = L(m) × W(m) × H(m)

For multiple cartons: Total CBM = CBM per carton × Quantity

Step-by-Step Process

Measure each carton: length, width, and height in inches.
Multiply all three dimensions together (result is in cubic inches).
Divide by 61,023.7 to get CBM per carton.
Multiply by carton quantity for total shipment CBM.

Why 61,023.7? The Conversion Explained

The divisor 61,023.7 comes from the relationship between inches and meters:

1 inch = 0.0254 meters (exact, by international definition)
Therefore 1 meter = 1 ÷ 0.0254 = 39.3701 inches
1 cubic meter = 39.3701³ = 61,023.74 cubic inches

When you divide cubic inches by 61,023.74, you are converting from in³ to m³. Both methods (dividing by 61,023.7 or converting each dimension by ×0.0254) give identical results. The single-divisor approach is faster for bulk calculations.

Worked Examples — US Standard Carton Sizes

Example 1: Standard US Shipping Carton

A carton measuring 24" × 18" × 12":

24 × 18 × 12 = 5,184 in³
5,184 ÷ 61,023.7 = 0.0849 CBM per carton

Example 2: Medium US Carton

A carton measuring 20" × 16" × 14":

20 × 16 × 14 = 4,480 in³
4,480 ÷ 61,023.7 = 0.0734 CBM per carton

Example 3: Multiple Cartons

200 cartons each measuring 18" × 14" × 10":

Single carton: 18 × 14 × 10 = 2,520 in³ ÷ 61,023.7 = 0.04129 CBM
200 cartons: 0.04129 × 200 = 8.258 CBM total

Use our CBM Calculator — select "in" from the unit dropdown and enter your dimensions in inches. The calculator converts and totals automatically.

Inches to CBM Quick Reference Table

Common US carton sizes and their CBM equivalent:

L × W × H (inches)	Cubic Inches	CBM per unit	CBM for 100 units
12 × 8 × 8	768	0.01259	1.259
16 × 12 × 10	1,920	0.03147	3.147
18 × 14 × 10	2,520	0.04129	4.129
20 × 16 × 14	4,480	0.07341	7.341
24 × 18 × 12	5,184	0.08494	8.494
24 × 18 × 18	7,776	0.12742	12.742
36 × 24 × 24	20,736	0.33980	33.980
48 × 40 × 48	92,160	1.51000	151.000
48 × 40 × 60	115,200	1.88758	188.758
60 × 48 × 48	138,240	2.26500	226.500

Using Our Calculator with Inch Dimensions

The CBM calculator at calculatecbm.com supports inch input directly. In the unit selector on each row, switch from "cm" to "in" and enter your dimensions as-is. The calculator applies the ÷61,023.7 conversion and returns CBM, volumetric weight, and container utilization for your shipment.

If your packing list has a mix of units — some items measured in inches, others in centimeters — you can set each row independently. There is no need to pre-convert everything to one unit.

For guidance on how CBM feeds into freight cost, see What is CBM in shipping and how to calculate CBM in cm for the centimeter equivalent of this guide.

Calculate CBM in Inches — Select 'in' in the Unit Dropdown
Enter your inch dimensions directly. Instant CBM, volumetric weight, and W/M tons.
Open CBM Calculator →

Frequently Asked Questions

CBM = (L × W × H in inches) ÷ 61,023.7. Example: 24 × 18 × 12 inches = 5,184 ÷ 61,023.7 = 0.0849 CBM. For multiple cartons, multiply by quantity.

1 CBM = 61,023.74 cubic inches. This is because 1 meter = 39.3701 inches, and 39.3701³ ≈ 61,023.74. Multiply CBM × 61,023.74 to convert to cubic inches; divide cubic inches by 61,023.74 to get CBM.

61,023.7 is the number of cubic inches in 1 cubic meter, derived from (1 ÷ 0.0254)³ = 39.3701³. Dividing your cubic inch volume by this constant gives you the equivalent volume in cubic meters (CBM).

1 inch = 0.0254 meters exactly. To convert each inch dimension to meters before calculating CBM, multiply by 0.0254, then calculate L(m) × W(m) × H(m). This gives the same result as dividing cubic inches by 61,023.7.

No — CBM is universal for international freight. US domestic LTL carriers use cubic feet and freight class instead of CBM. For all international ocean or air shipments, CBM is standard regardless of whether your source dimensions are in inches or centimeters.

Use whichever unit appears on your packing list or supplier documentation. US suppliers use inches; Asian and European suppliers use centimeters. Both give identical CBM when the correct formula is applied. Our calculator accepts both.

How to Calculate CBM in Inches — Formula & Examples