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GPH to mL/h Converter

Enter the flow rate in gph below to convert it to ml/h.

Convert GPH (US) to mL/h

Enter a value in gph (us) (GPH) to convert to ml/h (mL/h).

Result
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18,927.05892ml/h
5 GPH = 18,927.05892 mL/h
Result updates automatically
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Suggested Conversions
Reference:NIST SP 811 (NIST SP 811 App. B.9 (Volume Divided by Time))
[1–3] ↓

US Gallons per Hour to Milliliters per Hour Conversion Table

Table showing various us gallons per hour measurements converted to ml/h. Click any preset value or arrow to load it into the converter.

How to Convert GPH to mL/h

To convert gph to ml/h, multiply the flow rate by the following conversion ratio: 3,785.411784 ml/h/us gallons per hour.

Since one us gallons per hour is equal to 3,785.411784 ml/h, you can use this simple formula to convert:

ml/h = gph × 3,785.411784

The flow rate in ml/h is equal to the flow rate in gph multiplied by 3,785.411784.

For example, here's how to convert 5 gph to ml/h using the formula above.

ml/h = (5 GPH × 3,785.411784) = 18,927.05892 mL/h

How Many mL/h Are in a US Gallons per Hour?

There are 3,785.411784 ml/h in a us gallons per hour, which is why we use this value in the formula above.

1 GPH = 3,785.411784 mL/h|1 mL/h = 0.000264172 GPH

Our us gallons per hour to milliliters per hour calculator automatically converts your flow rate measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.

GPH and ml/h are both units used to measure flow rate. Keep reading to learn more about each unit.

What Is a US Gallons per Hour?

A us gallons per hour is a unit of flow rate equal to 0.0630902 liters per minute (L/min), the base unit for flow rate. Equal to 1/60 GPM (0.06309 L/min). [1]

The us gallons per hour is classified as a US customary unit of flow rate. GPH can be abbreviated as GPH; for example, 1 us gallons per hour can be written as 1 GPH.

When working with gph (GPH) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.

In practice, gph (GPH) are widely used across standard flow rate applications within US customary workflows, engineering documentation, and technical data sheets.

What Is a Milliliters per Hour?

A milliliters per hour is a unit of flow rate equal to 1/60,000 of a liters per minute (0.000016667 L/min). Medical IV infusion pump rate unit. [2]

The milliliters per hour is classified as a metric and SI-compatible unit of flow rate. mL/h can be abbreviated as mL/h; for example, 1 milliliters per hour can be written as 1 mL/h.

In the metric system, "milli" is the standard SI prefix for thousandths, or 10⁻³. This makes the milliliters per hour (mL/h) a convenient decimal multiple of the liters per minute (L/min).

In practice, ml/h (mL/h) are widely used across fine-tolerance laboratory, analytical, and micro-scale flow rate measurements within SI metric workflows, engineering documentation, and technical data sheets.

When converting flow rate between gph (GPH) and ml/h (mL/h), keep full floating-point precision (1 GPH = 3,785.411784 mL/h; 1 mL/h = 0.000264172 GPH) during intermediate calculations and round only the final milliliters per hour figure to match your instrument tolerance.

More US Gallons per Hour & Milliliters per Hour Conversions

Need to calculate in the opposite direction? Use our ml/h to gph (us) calculator to switch your starting unit immediately. You can also explore related tools such as converting ml/h to gph (us), converting liters per minute to gpm (us), or converting gpm (us) to liters per minute.

Frequently Asked Questions

There are 3,785.41178 ml/h (mL/h) in 1 us gallons per hour (GPH). Conversely, 1 milliliters per hour (mL/h) is equal to 0.00026417 gph (GPH).

References

NIST · BIPM · ISO
  1. [1]
    NIST SP 811 (NIST SP 811 App. B.9 (Volume Divided by Time))·Flow Rate Metrology Standard — GPH (US) (GPH) to mL/h (mL/h)
    NIST SP 811 Standard
  2. [2]
    NIST OWM (SI Units — Volume & Flow Capacity)·Unit Specifications: US Gallons per Hour (GPH) (GPH) & Milliliters per Hour (mL/h)
    NIST OWM Specification
  3. [3]
    BIPM (Coherent Volumetric Flow Units (m³/s))·Conversion Factors & Mathematical Basis (GPH to mL/h)
    BIPM Reference
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