Physiology Unit Conversions

Human Physiology • Foundations of Physiology

Written by STEM Calculators Team Published March 15, 2026 Updated March 15, 2026

Physiology unit conversions

Convert practical physiology units for volume, mass, lab concentrations, time, pressure, temperature, osmolarity, and mmol/L-style values. A single conversion and an optional batch CSV/paste workflow are included.

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Target unit

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Prefer scientific notation Show nearby equivalent units

Temperature conversions use formulas with offsets; all other supported families use direct multiplicative factors.

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Paste rows as value,source,target. A header row is allowed. CSV upload fills the same box.

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Physiology unit conversions

Physiology unit conversions keep the same physical quantity while changing only the reporting unit. This supports correct interpretation of lab values, body-fluid measurements, pressure readings, temperature scales, and time-based rates without mixing incompatible units.

The calculator converts a selected value from one supported unit to another and reports the converted value, the factor or formula used, nearby equivalent values, and the step-by-step dimensional analysis.

Core definitions and formulas

Most conversions in this tool are multiplicative. A source value is multiplied by a unit factor so the original unit cancels and the target unit remains.

\[ \begin{aligned} \text{target value} &= \text{source value} \cdot \text{conversion factor} \end{aligned} \]

Temperature is different because the scales do not share the same zero point, so an offset must be included.

\[ \begin{aligned} T_{F} &= T_{C} \cdot \frac{9}{5} + 32 \\ T_{K} &= T_{C} + 273.15 \\ T_{C} &= \left(T_{F} - 32\right) \cdot \frac{5}{9} \end{aligned} \]

Here, T is temperature, T_C is degrees Celsius, T_F is degrees Fahrenheit, and T_K is kelvin. Other supported families include volume, mass, concentration, time, pressure, osmolarity, and amount concentration.

How to interpret results

A larger or smaller number after conversion does not mean the physiology changed. It only means the same quantity is being expressed on a different scale, such as mL instead of L, mmHg instead of kPa, or mg/dL instead of g/L.

Common units in this calculator include µL, mL, dL, L, µg, mg, g, mg/dL, g/L, ng/mL, µg/L, s, min, h, day, mmHg, kPa, atm, °C, °F, K, mOsm/L, Osm/L, mmol/L, and mol/L. The outputs are most useful when checking whether a value has been reported in the expected unit family before moving to later physiology calculations.

Do not convert between unrelated families such as pressure and volume.
Temperature requires a formula with an offset, not only a scale factor.
Rounding too early can distort small concentration or osmolarity values.
Negative temperatures below absolute zero are not physically valid.

A quick example: 95 mg/dL becomes 0.95 g/L because 1 mg/dL = 0.01 g/L, so \(95 \cdot 0.01 = 0.95\).

This tool is useful for foundational physiology, lab interpretation, and preparation for later rate, compartment, or transport calculations. It is not designed for drug-dosing formulas, blood gas interpretation, or chemistry conversions that require molar mass and analyte-specific relationships.

Frequently Asked Questions

What is the difference between a unit conversion and a physiology formula?

A unit conversion changes only the reporting scale of the same physical quantity. A physiology formula combines variables to compute a new quantity such as flow, clearance, or membrane potential.

How do you convert mg/dL to g/L?

Use the factor 1 mg/dL = 0.01 g/L. Multiply the mg/dL value by 0.01 to get the result in g/L.

Why are temperature conversions different from other unit conversions?

Temperature scales have different zero points, so they need both multiplication and an additive offset. For example, degrees Fahrenheit and degrees Celsius are not related by a single constant factor.

When should mmHg be converted to kPa or atm?

mmHg is common for blood pressure and many physiology readings, while kPa and atm are often useful in gas-law or physics-based contexts. Converting helps keep later calculations in consistent units.

What happens if the source and target units are from different families?

The conversion is not physically meaningful, so the calculator should reject it. Volume, pressure, time, temperature, and concentration must stay within their own families unless a separate formula relates them.

Physiology Unit Conversions

Physiology unit conversions

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Frequently Asked Questions