Crop Yield Estimator
Step out of the truck, count ears and kernels, type 3 numbers, get your estimated bu/acre. Includes manure nutrient value by type.
Corn Yield Estimate
Yield Component Method
Quick-fill scenario
Measure this row length for 1/1000th acre
17 ft 5 in
Count every harvestable ear in this length
ears
rows
kernels
factor
Large kernels — modern hybrids, ideal conditions75–80
Average kernels — typical season80–85
Small / stressed kernels85–90
Popcorn / specialty90–100
spots
Estimated Yield
218
bu / acre
32 ears × 16 rows × 34 kernels = 17,408 kernels/1000th ac — 17,408 ÷ 80 = 217.6 bu/ac
Soybean Yield Estimate
Pod Count Method
Quick-fill scenario
Measure this row length for 1/1000th acre
17 ft 5 in
Count every plant in this length
plants
pods
seeds/pod
seeds/lb
Large seed varieties2,200–2,500
Average2,500–2,800
Small seed varieties2,800–3,200
Estimated Yield
66
bu / acre
105 plants × 38 pods × 2.5 seeds = 9,975 seeds/1000th ac — 9,975,000 ÷ 2,500 seeds/lb = 3,990 lb ÷ 60 = 66.5 bu/ac
Manure Nutrient Value
Reference Prices
Using reference fertilizer prices — live prices load automatically
Select manure type
Typical nutrient content (per 1,000 gal)
Total N
25
lbs
P₂O₅
18
lbs
K₂O
17
lbs
Avail N yr 1
75%
of total
gal
acres
%
Total Nutrient Credit Value
—
total applied
—
per acre
N credit
—
P₂O₅ credit
—
K₂O credit
—
Select a manure type and enter quantity to see nutrient credit value.
Nutrient content from UW Extension averages. Actual values vary — test your manure for accurate planning. N availability reflects typical first-year plant-available fraction.
Field Scouting Guide
1 Pick 5+ spots across the field. Avoid end rows, waterways, and obviously good or bad areas.
2 Measure your row length for 1/1000th acre using the selector above. Pace it off at roughly 3 ft per stride.
3 For corn: Count every harvestable ear in that length. Pull 5+ representative ears and count kernel rows and kernels per row from butt to tip. Skip unfilled tip kernels.
4 For soybeans: Count every plant in that length. Pull 10+ representative plants and count total pods per plant.
5 Average your samples and enter the numbers above. Best done at R4–R5 (corn) or R6 (soybeans).
These are estimates. Actual yield can differ 10–20% due to kernel weight, harvest loss, moisture, tip-back, and stalk quality. More sample locations = better accuracy.
1/1000th Acre Row Lengths
Reference7.5" drill rows69 ft 8 in
10" drill rows52 ft 3 in
15" rows34 ft 10 in
20" rows26 ft 2 in
30" rows17 ft 5 in
36" rows14 ft 6 in
38" rows13 ft 9 in
Formula: 43,560 ft² ÷ 1,000 ÷ (row spacing in ft) = row length in feet
WI & MN State Yield Benchmarks
USDA NASS 5-yr Avg🌾 Wisconsin
Corn~155–170 bu/ac
Soybeans~45–50 bu/ac
🌾 Minnesota
Corn~185–200 bu/ac
Soybeans~48–52 bu/ac
Source: USDA NASS. 5-year state average. Use as a sanity check — field averages vary widely from the state mean.
Frequently Asked Questions
Use the yield component method: count ears in 1/1000th of an acre (17 ft 5 in of a 30-inch row), then count average kernel rows per ear and kernels per row on 5+ representative ears. Multiply ears × rows × kernels and divide by a correction factor (typically 75–90 depending on kernel size) to get estimated bushels per acre. Enter those three numbers in the Corn calculator above.
In 30-inch rows, 1/1000th of an acre is 17 feet 5 inches. For 36-inch rows it's 14 ft 6 in. For 20-inch rows it's 26 ft 2 in. The row-length selector in the calculator updates automatically. Formula: 43,560 sq ft ÷ 1,000 ÷ row width in feet = length in feet.
Start with 80 for most modern corn. Use 75–80 for large-kerneled, high-yield hybrids in a good year. Use 85–90 for small or stress-affected kernels. The correction factor accounts for how many kernels it takes to fill a 56-lb bushel — larger, heavier kernels mean a lower factor.
The best time is R4 (dough) to R5 (dent) stage — typically late July to mid-August in Wisconsin and Minnesota. Kernel rows and kernels per row are fully set, and fill is mostly complete. Estimates made before R4 tend to run high because tip kernels haven't fully set and may yet abort.
Expect 10–20% variance from harvested yield under normal conditions. The method tends to overestimate when significant tip-back, stalk rot, harvest losses, or late-season stress reduces kernel weight. Sampling 5 or more representative spots across a field dramatically improves accuracy vs. a single sample. Avoid end rows and obvious high/low spots.
Count plants in 1/1000th of an acre. Pull 10+ representative plants and count their pods. Use 2.5 seeds per pod and 2,500 seeds per pound as starting defaults. Math: plants × pods × 2.5 × 1,000 = seeds per acre. Divide by seeds/lb to get pounds per acre, then divide by 60 for bushels. Sample at R6 (full seed) for best accuracy.
It depends on manure type and current fertilizer prices. Liquid hog finishing slurry typically contains ~25 lbs total N, 18 lbs P₂O₅, and 17 lbs K₂O per 1,000 gallons. Dairy slurry runs about 19/8/19. At typical fertilizer prices, liquid hog slurry represents roughly $20–30 per 1,000 gallons in nutrient credits. Use the Manure Nutrient Value calculator above for a real-time estimate using current fertilizer prices.
Tip-back occurs when kernels at the ear tip fail to develop — usually from drought stress at silking (R1), excessive plant population, or nutrient stress. Tip kernels are the last to be pollinated and first to abort under stress. When you count kernels per row in the field, skip any unfilled tip kernels to avoid overestimating. Severe tip-back can reduce actual yield 10–20% below your calculator estimate.