Photosynthesis Rate Calculator

Work out photosynthesis rate instantly with clear inputs, formula shown and shareable results.

About Photosynthesis Rate Calculator

Converts collected oxygen volume into a leaf-area-normalised photosynthesis rate, including the micromole units used in gas exchange work.

Formula

Photosynthesis rate

Rate = oxygen volume / (leaf area x time); micromoles = volume (mL) / 22.4 x 1000 at standard temperature and pressure

Worked example

With the default values below, Photosynthesis Rate Calculator returns Photosynthesis rate of 0.96000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Oxygen collectedaccepts 0.01–1,000 mL: 12 mL
Leaf areaaccepts 0.1–10,000 cm2: 25 cm2
Durationaccepts 0.5–1,440 min: 30 min

Results

Photosynthesis rate: 0.96000 mL O2/cm2/h
Oxygen evolved per hour: 24.000 mL/h
Oxygen collected: 535.714 micromol
Rate: 119.048 micromol/m2/s

Step by step

1Values used
2Photosynthesis rate
3Photosynthesis rate= 0.96000 mL O2/cm2/h
4Oxygen evolved per hour= 24.000 mL/h
5Oxygen collected= 535.714 micromol
6Rate= 119.048 micromol/m2/s

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 5 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why express rates per unit leaf area?

It removes plant size from the comparison, isolating the physiological rate.

Is oxygen evolution equal to gross photosynthesis?

No. Measured evolution is net of respiration, so gross photosynthesis is higher.