How do you convert hectopascals to millipascals?

To convert hectopascals (hPa) to millipascals (mPa), multiply the pressure in hectopascals by 100,000 (millipascals = hectopascals × 100,000).

What is 5 hectopascals in millipascals?

5 hectopascals (5 hPa) is equal to 500,000 millipascals (500,000 mPa).

Which is larger, 1 hectopascal (hPa) or 1 millipascal (mPa)?

One hectopascal (hPa) is larger than one millipascal (mPa). Specifically, 1 hPa contains 100,000 mPa, whereas 1 mPa is 0.00001 hPa.

How do I convert back from millipascals (mPa) to hectopascals (hPa)?

To reverse the calculation from mPa to hPa, multiply your millipascal value by the inverse factor 0.00001 (or divide by 100,000). You can also click the Swap button in the tool above to flip directions in one click.

How many decimal places should I round hPa to mPa results to?

For everyday comparisons and quick estimates, rounding to 2 decimal places is usually sufficient (for example, 5 hPa ≈ 500,000.00 mPa). For engineering, laboratory, or machining specifications, select 4 or 6 decimals—or Scientific (10ⁿ) mode—in the calculator toolbar above.

Hectopascals to Millipascals Converter

Enter the pressure in hectopascals below to convert it to millipascals.

Millipascals to Hectopascals (mPa → hPa)

Convert Hectopascals to Millipascals

Enter a value in hectopascals (hPa) to convert to millipascals (mPa).

Value (hPa)

From

Result

•

500,000millipascals

5 hPa = 500,000 mPa

Result updates automatically

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Equivalent Measurements Across UnitsFor 5 hPa

Pascals500 Pa

Kilopascals0.5 kPa

Bars0.005 bar

PSI0.07252 psi

Atmospheres0.00493461 atm

Suggested Conversions

Reference:NIST SP 811 (NIST SP 811 App. B.9 (Pressure & Stress))

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Hectopascal to Millipascal Conversion Table

Table showing various hectopascal measurements converted to millipascals. Click any preset value or arrow to load it into the converter.

Hectopascals (hPa)	Millipascals (mPa)
0.0000001 hPa	0.01 mPa
0.0000002 hPa	0.02 mPa
0.0000003 hPa	0.03 mPa
0.0000004 hPa	0.04 mPa
0.0000005 hPa	0.05 mPa
0.0000006 hPa	0.06 mPa
0.0000007 hPa	0.07 mPa
0.0000008 hPa	0.08 mPa
0.0000009 hPa	0.09 mPa
0.00000001 hPa	0.001 mPa

How to Convert Hectopascals to Millipascals

To convert hectopascals to millipascals, multiply the pressure by the following conversion ratio: 100,000 millipascals/hectopascal.

Since one hectopascal is equal to 100,000 millipascals, you can use this simple formula to convert:

millipascals = hectopascals × 100,000

The pressure in millipascals is equal to the pressure in hectopascals multiplied by 100,000.

For example, here's how to convert 5 hectopascals to millipascals using the formula above.

millipascals = (5 hPa × 100,000) = 500,000 mPa

How Many Millipascals Are in a Hectopascal?

There are 100,000 millipascals in a hectopascal, which is why we use this value in the formula above.

1 hPa = 100,000 mPa|1 mPa = 0.00001 hPa

Our hectopascal to millipascal calculator automatically converts your pressure measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.

Hectopascals and millipascals are both units used to measure pressure. Keep reading to learn more about each unit.

What Is a Hectopascal?

A hectopascal is a unit of pressure equal to 100 pascals (Pa), the base unit for pressure. Equal to 100 Pascals (identical to 1 millibar). [1]

The hectopascal is classified as a metric and SI-compatible unit of pressure. Hectopascals can be abbreviated as hPa; for example, 1 hectopascal can be written as 1 hPa.

In the metric system, "hecto" is the standard SI prefix for hundreds, or 10². This makes the hectopascal (hPa) a convenient decimal multiple of the pascal (Pa).

In practice, hectopascals (hPa) are widely used across standard pressure applications within SI metric workflows, engineering documentation, and technical data sheets.

Learn more about hectopascals in our Pressure Converter.

What Is a Millipascal?

A millipascal is a unit of pressure equal to 1/1,000 of a pascal (0.001 Pa). One-thousandth of a Pascal. [2]

The millipascal is classified as a metric and SI-compatible unit of pressure. Millipascals can be abbreviated as mPa; for example, 1 millipascal can be written as 1 mPa.

In the metric system, "milli" is the standard SI prefix for thousandths, or 10⁻³. This makes the millipascal (mPa) a convenient decimal multiple of the pascal (Pa).

In practice, millipascals (mPa) are widely used across fine-tolerance laboratory, analytical, and micro-scale pressure measurements within SI metric workflows, engineering documentation, and technical data sheets.

Learn more about millipascals in our Pressure Converter.

When converting pressure between hectopascals (hPa) and millipascals (mPa), keep full floating-point precision (1 hPa = 100,000 mPa; 1 mPa = 0.00001 hPa) during intermediate calculations and round only the final millipascal figure to match your instrument tolerance.

More Hectopascal & Millipascal Conversions

Need to calculate in the opposite direction? Use our millipascals to hectopascals calculator to switch your starting unit immediately. You can also explore related tools such as converting millipascals to hectopascals, converting hectopascals to pascals, or converting hectopascals to inches of mercury.

Convert from Hectopascals

Convert to Millipascals

Frequently Asked Questions

There are 100,000 millipascals (mPa) in 1 hectopascal (hPa). Conversely, 1 millipascal (mPa) is equal to 0.00001 hectopascals (hPa).

Pressure Converter

Quick Info

Direct Factor: 1 hectopascal (hPa) equals 100,000 millipascals (mPa).
Inverse Factor: 1 millipascal (mPa) equals 0.00001 hectopascals (hPa).
Formula: millipascals = hectopascals × 100,000.
Verified Precision: Anchored to official NIST SP 811 and ISO/IEC 80000 standards.

Units Comparison

Hectopascal (hPa)

Equal to 100 Pascals (identical to 1 millibar).

Millipascal (mPa)

One-thousandth of a Pascal.

Pascal (Pa)

SI derived unit of pressure equal to 1 Newton per square meter (N/m²).

References

[1]NIST SP 811 · NIST SP 811 App. B.9 (Pressure & Stress)
Source
[2]NIST CUU · Derived SI Unit: Pascal (Pa)
Source
[3]BIPM · SI Brochure (9th Ed.) — Mechanics
Source

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References

NIST · BIPM · ISO

[1]
NIST SP 811 (NIST SP 811 App. B.9 (Pressure & Stress))·Pressure Metrology Standard — Hectopascals (hPa) to Millipascals (mPa)
NIST SP 811 Standard
[2]
NIST CUU (Derived SI Unit: Pascal (Pa))·Unit Specifications: Hectopascal (hPa) & Millipascal (mPa)
NIST CUU Specification
[3]
BIPM (SI Brochure (9th Ed.) — Mechanics)·Conversion Factors & Mathematical Basis (hPa to mPa)
BIPM Reference

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