ToolsPlant population
This PropelMapper calculator turns your plant count, row length and row width into plants per acre for the sampled area.
The starting sample shows the conversion. It does not set a target population or make a replant recommendation.
| Measure | Result |
|---|---|
| Plant populationRounded to the nearest 100 | 32,000 plants / ac |
| Plants per foot of row | 1.8 plants / ft |
| 1/1000 acre of row at this width | 17.4 ft |
You count the plants in a measured length of row and write down the row width. You enter those three values here to convert the sample to plants per acre. The number describes the measured sample.
In your visit note, you say where you counted and describe any gaps or delayed plants. You can include the calculator result in that note rather than leaving the grower with an average that hides the patch you inspected.
After the note uploads, we prepare the report for you to read and add your advice to. You decide whether the sample represents the field and what other counts you need.
“Stand-count example: 32 plants in 17.4 feet of a 30-inch row. The calculation is about 32,044 plants per acre before display rounding. This sample is from the wet patch, so I am keeping it separate from the other counts.”
A count of 32 plants in 17.4 feet of 30-inch row gives about 32,044 plants per acre before display rounding.
This directed sample describes the wet patch and is kept separate from the other counts.
A count of 32 plants in 17.4 feet of 30-inch row gives about 32,044 plants per acre before display rounding.
This directed sample describes the wet patch and is kept separate from the other counts.
After your review
Multiply row length in feet by row width in feet to find square feet sampled. Divide the plant count by that area, then multiply by 43,560 square feet per acre. We use the entered length, including when it differs from a rounded 1/1000-acre convention (Nebraska stand-count method).
Nebraska Extension describes repeated counts in measured areas. The raw counts and locations let a summary distinguish representative samples from a directed check of a weak patch.
A 17.4-foot length of 30-inch row covers 43.5 square feet. Counting 32 plants gives about 32,044 plants per acre, displayed to the nearest hundred.
For a soybean hoop sample, use a separate area calculation: π × radius in feet squared. A 30-inch inside diameter encloses about 4.91 square feet. Fourteen plants give about 124,236 plants per acre using the unrounded area. The calculator above uses row dimensions; Iowa State’s linked method covers hoop sampling.