Field, Machinery & Storage

Combine Grain Loss Calculator

Estimate combine harvest loss from grain collected in a measured sample area and compare it with field yield.

Free agriculture calculator

Combine Grain Loss Calculator

How to use the Combine Grain Loss Calculator

  1. Enter the requested field, crop, animal, equipment, or cost information.
  2. Keep every value in the unit shown beside its field.
  3. Select Calculate and review each result and assumption.
  4. Verify important decisions with local records, labels, extension guidance, or a qualified adviser.

Formula and method

Loss (kg/ha) = sample grain (g) ÷ sample area (m²) × 10. Loss % = kg/ha ÷ field yield (kg/ha) × 100.

This weight-based method scales a measured loss sample to one hectare, then compares the loss with the entered field yield. It avoids crop-specific kernel-count assumptions.

Worked example

An 80 g loss sample from 10 m² equals 80 kg/ha. At a 5 t/ha field yield, that is about 1.6% loss.

Understanding the result

Treat the calculated values as a planning estimate. Compare them with your field records, product information, local conditions and operational capacity before acting.

Important: Use representative samples collected with a consistent method. Separate pre-harvest/header loss from machine loss when diagnosing combine performance, and follow manufacturer or extension calibration guidance.

Frequently asked questions

How does this combine grain loss calculator work?

It converts the weight of grain found in a measured ground area into kilograms per hectare, then compares that loss with the field yield you enter.

Why use a weight-based grain loss calculation?

A weight-based sample can be used across crops without relying on crop-specific kernels-per-bushel or seed-count assumptions, provided the sample area is measured accurately.

Does the result include header and pre-harvest loss?

It depends on where and how you collect the sample. To diagnose combine performance, measure losses consistently and separate pre-harvest/header loss from machine loss where possible.

Can the calculator estimate the money lost?

Yes. Enter an optional crop price per tonne to estimate the field value associated with the calculated grain loss.