Threshing Output Calculator

Work out threshing output instantly with clear inputs, formula shown and shareable results.

About Threshing Output Calculator

A thresher is rated on total crop fed in, of which only the grain fraction — around 35-45% for wheat and paddy — becomes saleable output. Threshing efficiency accounts for grain left in the ear and passed out with the straw, and even 2% inefficiency on a long day is a meaningful loss.

Formulas

Threshing output

Grain per hour = feed rate x grain fraction x threshing efficiency

Loss

Unthreshed grain = feed rate x grain fraction x (1 - efficiency) x hours

Worked example

With the default values below, Threshing Output Calculator returns Grain Output of 3.763. Change any input above and every figure here is recalculated in your browser.

Inputs used

Machine Feed Rateminimum 1 kg total crop/hour: 1,200 kg total crop/hour
Grain Fraction Of Total Cropaccepts 1–100 %: 40 %
Operating Hoursminimum 0.1 h: 8 h
Threshing Efficiencyaccepts 50–100 %: 98 %

Results

Grain Output: 3.763
Grain Output Per Hour: 470.40
Straw And Chaff Per Hour: 720.00
Grain Left Unthreshed: 76.80

Step by step

1Values used
2Threshing output
3Loss
4Grain Output= 3.763
5Grain Output Per Hour= 470.40
6Straw And Chaff Per Hour= 720.00
7Grain Left Unthreshed= 76.80

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Threshers cause severe entanglement injuries. Keep all guards fitted, never feed by hand into an unguarded cylinder and stop the machine before clearing a blockage.

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

Threshers cause severe entanglement injuries. Keep all guards fitted, never feed by hand into an unguarded cylinder and stop the machine before clearing a blockage.

Frequently Asked Questions

How do I check threshing efficiency?

Collect the straw output from a timed run, hand-thresh a sample and weigh the grain still attached. Efficiency is grain recovered divided by total grain in the sample.

What causes broken grain?

Excessive cylinder speed and too tight a concave clearance. Broken grain is downgraded in the market, so tune for the lowest speed that still threshes cleanly.