N = PV/RT Calculator for Chemistry

Ideal Gas Law Calculator Form

Select the unknown variable. The matching value field becomes locked, while its unit still controls how the result is displayed.

Solve for

Pressure value

Pressure unit

Volume value

Volume unit

Temperature value

Temperature unit

Amount value

Amount unit

Decimal places

Graph points

Example Data Table

These chemistry examples apply the ideal gas law to common unit combinations and standard classroom scenarios.

Pressure	Volume	Temperature	Calculated n
1 atm	22.414 L	0 C	1 mol
1 atm	24.465 L	25 C	1 mol
2 atm	10 L	27 C	0.812 mol
101.325 kPa	5 L	20 C	0.2079 mol
750 mmHg	2.5 L	35 C	0.0976 mol

Formula Used

The ideal gas law is PV = nRT. Rearranging it gives the exact form you asked for: n = PV / RT.

In this equation, P is absolute pressure, V is gas volume, n is amount in moles, R is the gas constant, and T is absolute temperature in Kelvin.

This calculator converts every entered unit to SI first. That means pressure becomes pascals, volume becomes cubic meters, temperature becomes Kelvin, and amount becomes moles before solving.

Useful rearrangements are listed below:

n = PV / RT
P = nRT / V
V = nRT / P
T = PV / nR

The gas constant used here is 8.314462618 J·mol⁻¹·K⁻¹.

How to Use This Calculator

Choose the variable you want to calculate.
Enter the other three known values.
Select the correct unit for each measurement.
Pick the amount of rounding you want.
Press Calculate to show the answer above the form.
Review the SI conversion rows for verification.
Inspect the Plotly graph to study the trend.
Download the result or example table as CSV or PDF.

For reliable chemistry work, use absolute pressure and confirm that the data belongs to one gas sample under the same conditions.

FAQs

1. What does n represent in the equation?

n is the amount of substance in moles. One mole represents a fixed number of particles. This calculator can also display smaller values in millimoles.

2. Why is temperature converted to Kelvin?

The ideal gas law uses absolute temperature. Celsius and Fahrenheit are converted to Kelvin internally, then any solved temperature is converted back to your selected scale.

3. Which pressure units can I use here?

You can enter Pa, kPa, bar, atm, or mmHg. The page converts each one to pascals so the equation stays consistent and accurate.

4. Can this page solve pressure, volume, and temperature too?

Yes. Pick the unknown from the Solve for menu. The matching value field locks automatically, and the calculator solves for that variable.

5. Why do my answers look unrealistic?

Most issues come from wrong units, non-absolute temperature, or pressure entered on the wrong scale. Recheck every unit and confirm the gas values match one state.

6. Does this equation work for all gases?

It works best when gas behavior is close to ideal. Extremely high pressure or strong intermolecular effects may require a real-gas model instead.

7. What does the graph help me understand?

The graph shows how the solved variable changes when one related input varies while other conditions stay fixed. It is useful for quick trend checks.

8. Are CSV and PDF exports useful for lab notes?

Yes. They help with homework, revision sheets, and draft lab records. Still follow your class rules for significant figures, formatting, and final reporting.