Length · Unit Converter

Convert Square Millimeter to Katha (Bihar)

Convert square millimeters to kathas instantly. 1 square millimeter = 7.90889e-9 katha (bihar) — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Katha (Bihar) to Square Millimeter converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Girish V Kulkarni Ph.D.
Length category 2 min read Published Last reviewed Updated

Units explained

Metric / SI

Square Millimeter

What is a square millimeter?

A square millimeter is a metric unit of area equal to 10⁻⁶ m² (1 mm × 1 mm). It is widely used in engineering, electronics, and small-scale technical work.

Origin of the square millimeter

Derived by squaring the millimeter, defined as 1/1000 of a meter. The milli- prefix comes from the Latin 'mille' (thousand).

Where it is used

Square millimeters express PCB trace cross-sections, the area of small mechanical features in CAD drawings, biological sample sizes, and material thicknesses.

When and where it was developed

Millimeter has been part of the metric system since 1795.

Indian Subcontinent

Katha (Bihar)

What is a katha (bihar)?

A Bihar katha is a traditional unit of land area equal to approximately 126.44 m² (1/20 of a pucca bigha in Bihar).

Origin of the katha (bihar)

Defined as 1/20 of the Bihar pucca bigha. Like other regional kathas, the actual size varies with the local bigha.

Where it is used

Bihar kathas appear in land records and property transactions across Bihar.

When and where it was developed

Traditional regional unit.

Square Millimeter to Katha (Bihar) conversion formula

The relationship between square millimeters and kathas:

1 mm² = 7.90889e-9 katha
1 katha = 1.2644e+8 mm²

To convert square millimeters to kathas, multiply the value in square millimeters by 7.90889e-9. To reverse, multiply kathas by 1.2644e+8.

How to use this converter

Type a value into the calculator. The result in kathas updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Katha (Bihar) to Square Millimeter converter for the reverse direction.

Step-by-step: convert square millimeters to kathas

  1. Write down the value in square millimeters (mm²).
  2. Multiply that value by the factor 7.90889e-9.
  3. The product is the equivalent value in kathas (katha).
  4. To reverse, multiply the katha (bihar) value by 1.2644e+8.

Worked examples

Example 1 — Convert 1 mm² to katha:
1 × 7.90889e-9 = 7.90889e-9 katha

Example 2 — Convert 100 mm² to katha:
100 × 7.90889e-9 = 7.90889e-7 katha

Real-world example — Plastic-film thickness alternates

A 150-square millimeter plastic film converts cleanly to kathas — useful for packaging buyers reconciling supplier datasheets across metric and US measurement systems.

150 mm² × 7.90889e-9 = 1.186333e-6 katha

Real-world example — Hair-width scale measurements

A 70-square millimeter measurement (about the diameter of a human hair) is the kind of value materials engineers regularly express in adjacent micro-scale units like kathas for direct comparison across supplier datasheets.

70 mm² × 7.90889e-9 = 5.536223e-7 katha

Real-world example — Paper and film thicknesses

At the thickness of office paper (roughly 3 square millimeters), converting between sub-millimeter units is routine for packaging and printing buyers comparing quotes from metric and US suppliers.

3 mm² × 7.90889e-9 = 2.372667e-8 katha

Square Millimeter to Katha (Bihar) conversion table

Standard reference values for converting square millimeters to kathas:

Square Millimeter [mm²]Katha (Bihar) [katha]
0.017.90889e-11
0.17.90889e-10
17.90889e-9
21.581778e-8
32.372667e-8
43.163556e-8
53.954445e-8
107.90889e-8
201.581778e-7
302.372667e-7
403.163556e-7
503.954445e-7
1007.90889e-7
5003.954445e-6
10007.90889e-6

Frequently asked questions

How many kathas is 1 square millimeter?
1 square millimeter equals 7.90889e-9 katha (bihar).
How do I convert square millimeters to kathas?
Multiply the value in square millimeters by 7.90889e-9 to get kathas.
How do I convert kathas back to square millimeters?
Multiply the value in kathas by 1.2644e+8, or use the Katha (Bihar) to Square Millimeter converter.
How many kathas is 100 square millimeters?
100 square millimeters equals 7.90889e-7 kathas, because 100 × 7.90889e-9 = 7.90889e-7.

Convert Square Millimeter to other area units

Show all Square Millimeter conversions
Metric / SI (15 units)
Imperial / US Customary (15 units)
US Survey (5 units)
Indian Subcontinent (16 units)
Other Regional (10 units)
Scientific / Physics (5 units)
Historical / Pre-metric European (6 units)

Sources & references

Conversion factor (1 mm² = 7.90889e-9 katha) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.