# Predicting Wine Grape Crops - Metric

## This calculator can help estimate the yield in tons per hectare.

The **harvest cluster weight method** is based on the number of producing vines per hectare, the average number of clusters per vine, and the average cluster weight at harvest from previous years to predict the yield in tons per hectare for the current season.

The **lag phase cluster weight method** is based on the number of producing vines per hectare, the average number of clusters per vine, and the average cluster weight at the lag phase state of the grape with the use of a multiplier to predict the yield in tons per hectare for the current season. Cluster weights will double from lag phase to harvest time. The multiplier in this calculator is set at 2 but this number can vary depending on various factors.

*Sampling method and amounts of samples taken to obtain averages is beyond the scope of this calculator. Accuracy counts!*

### Estimate Grape Yield Using Lag-Phase or Harvest Cluster Weight Method

#### The Calculator

- Select your method
- The multiplier in this calculator is set at 2 but can be changed. It only comes in play when using the lag phase method
- Row spacing in metres
- Vine spacing in metres. 3 and 4 will determine number of vines per hectare
- Enter the number of non bearing or missing vines
- Enter the average amount of clusters per vine
- Enter the average weight of these clusters in grams

#### The Results

The result of the calculation will be the yield in tons per hectare of the grape crop.