Length · Unit Converter

Convert Pole to Microinch

Convert poles to microinches instantly. 1 pole = 1.98e+8 microinch — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Microinch to Pole 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

Imperial / US Customary

Pole

What is a pole?

A pole is an Imperial unit of length identical to the rod and perch — 16.5 feet (about 5.03 m). The names are regional and historical variants for the same measurement.

Origin of the pole

The pole derives from medieval English land-surveying. The name comes from the physical wooden pole used by surveyors to lay out the unit on the ground.

Where it is used

Poles appear in historical land records, particularly older US public-land surveys. Functionally identical to rod and perch in all calculations.

When and where it was developed

Medieval English surveying origin; identical to the rod since 1620; became exact via the 1959 International Yard and Pound Agreement.

Imperial / US Customary

Microinch

What is a microinch?

A microinch is an Imperial unit of length equal to one millionth of an inch (2.54×10⁻⁸ m). It is used almost exclusively in surface-finish specifications for precision machining and optical components.

Origin of the microinch

The microinch is derived from the inch using the SI-style prefix micro- to denote one millionth. Standardised through the 1959 International Yard and Pound Agreement, which fixed the inch at exactly 25.4 mm.

Where it is used

Microinches express surface roughness (Ra values) in US-based precision manufacturing — typical machined surfaces are 16–125 µin. Optical components and bearing races are often specified to 1–4 µin Ra.

When and where it was developed

Used in US precision-manufacturing literature throughout the 20th century; value became exact in 1959 when the inch was fixed at 25.4 mm via the International Yard and Pound Agreement.

Pole to Microinch conversion formula

The relationship between poles and microinches:

1 pole = 1.98e+8 µin
1 µin = 5.050505e-9 pole

To convert poles to microinches, multiply the value in poles by 1.98e+8. To reverse, multiply microinches by 5.050505e-9.

How to use this converter

Type a value into the calculator. The result in microinches updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Microinch to Pole converter for the reverse direction.

Step-by-step: convert poles to microinches

  1. Write down the value in poles (pole).
  2. Multiply that value by the factor 1.98e+8.
  3. The product is the equivalent value in microinches (µin).
  4. To reverse, multiply the microinch value by 5.050505e-9.

Worked examples

Example 1 — Convert 1 pole to µin:
1 × 1.98e+8 = 1.98e+8 µin

Example 2 — Convert 100 pole to µin:
100 × 1.98e+8 = 1.98e+10 µin

Real-world example — Meter to nanoscale

One pole equals one billion microinches. Physics curricula use this conversion to teach orders of magnitude when introducing the electromagnetic spectrum.

1 pole × 1.98e+8 = 1.98e+8 µin

Real-world example — Human-scale to atomic dimensions

One pole equals one billion microinches — the canonical metric conversion bridging everyday objects and atomic-scale features in physics, chemistry, and electronics.

1 pole × 1.98e+8 = 1.98e+8 µin

Pole to Microinch conversion table

Standard reference values for converting poles to microinches:

Pole [pole]Microinch [µin]
0.011980000.0000000002
0.11.98e+7
11.98e+8
23.96e+8
35.94e+8
47.92e+8
59.9e+8
101.98e+9
203.96e+9
305.94e+9
407.92e+9
509.9e+9
1001.98e+10
5009.9e+10
10001.98e+11

Frequently asked questions

How many microinches is 1 pole?
1 pole equals 1.98e+8 microinch.
How do I convert poles to microinches?
Multiply the value in poles by 1.98e+8 to get microinches.
How do I convert microinches back to poles?
Multiply the value in microinches by 5.050505e-9, or use the Microinch to Pole converter.
How many microinches is 100 poles?
100 poles equals 1.98e+10 microinches, because 100 × 1.98e+8 = 1.98e+10.

Convert Pole to other length units

Show all Pole conversions

Sources & references

Conversion factor (1 pole = 1.98e+8 µin) verified against the following authoritative sources:

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