Corn Planting Rate Calculator

Corn Planting Rate Calculator

The desired number of harvestable ears/plants per acre.

Germination rate minus field loss.

Calculation Results

Required Seeding Rate

0 seeds/acre

Seed Spacing

0 inches

Linear Feet per Acre

0 ft

Estimated Cost per Acre

$0.00

function calculateCornRate() { // Get inputs var targetPop = parseFloat(document.getElementById('targetPop').value); var rowWidth = parseFloat(document.getElementById('rowWidth').value); var emergenceRate = parseFloat(document.getElementById('emergenceRate').value); var seedsPerBag = parseFloat(document.getElementById('seedsPerBag').value); var costPerBag = parseFloat(document.getElementById('costPerBag').value); // Basic Validation if (isNaN(targetPop) || isNaN(rowWidth) || isNaN(emergenceRate)) { alert("Please enter valid numbers for Target Population, Row Width, and Emergence."); return; } // Calculation Logic // 1. Calculate Required Seeding Rate (Target / (Emergence % / 100)) // Example: 32,000 / 0.95 = 33,684 seeds needed var requiredSeedingRate = targetPop / (emergenceRate / 100); // 2. Constants var sqFtPerAcre = 43560; var sqInchesPerAcre = 6272640; // 43560 * 144 // 3. Calculate Linear Feet of Row per Acre // Formula: 43,560 / (Row Width in Ft) // Row Width in Ft = Row Width / 12 var rowWidthFt = rowWidth / 12; var linearFeetPerAcre = sqFtPerAcre / rowWidthFt; // 4. Calculate Seed Spacing (Inches) // Formula: Linear Feet per Acre * 12 / Seeding Rate var seedSpacing = (linearFeetPerAcre * 12) / requiredSeedingRate; // 5. Calculate Cost per Acre // (Seeding Rate / Seeds per Bag) * Cost per Bag var costPerAcre = 0; if (!isNaN(seedsPerBag) && !isNaN(costPerBag) && seedsPerBag > 0) { costPerAcre = (requiredSeedingRate / seedsPerBag) * costPerBag; } // Display Results document.getElementById('resSeedingRate').innerHTML = Math.round(requiredSeedingRate).toLocaleString() + " seeds/acre"; document.getElementById('resSpacing').innerHTML = seedSpacing.toFixed(2) + " inches"; document.getElementById('resLinearFeet').innerHTML = Math.round(linearFeetPerAcre).toLocaleString() + " ft"; document.getElementById('resCost').innerHTML = "$" + costPerAcre.toFixed(2); // Show results div document.getElementById('resultsArea').style.display = 'block'; }

Achieving the maximum potential yield in corn production starts at planting. The Corn Planting Rate Calculator helps agronomists and farmers determine the precise seeding rate required to achieve a desired final stand count, factoring in row width and expected emergence rates. Unlike soybeans, corn does not compensate well for gaps in the row, making precision planting critical.

How to Calculate Corn Seeding Rate

To calculate the ideal planting rate, you must work backward from your harvest goal (Final Stand). No planter achieves 100% germination and emergence due to field conditions, seed vigor, and pests. The basic formula used in agronomy is:

Seeding Rate = Target Final Population ÷ (Emergence % ÷ 100)

For example, if you aim for a final stand of 32,000 plants per acre and you anticipate 95% emergence (a combination of germination rate and field survival), you need to plant approximately 33,684 seeds per acre.

Understanding Seed Spacing

Once the seeding rate is determined, calibrating the planter requires knowing the target seed spacing within the row. This distance varies significantly based on row width.

• 30-inch rows: The most common row spacing. At 32,000 population, seeds are spaced roughly 6.5 inches apart.
• 20-inch rows: Narrower rows allow for greater spacing between plants within the row for the same population, potentially reducing plant-to-plant competition.

Key Factors Influencing Planting Rate

1. Hybrid Specifics: Some flex-ear hybrids perform well at lower populations (28k-30k), while fixed-ear hybrids may require higher populations (34k-36k) to maximize yield.
2. Soil Type: Highly productive soils with good water-holding capacity can support higher populations than drought-prone sandy soils.
3. Economic Threshold: As seed costs rise, the "economic optimum" population may be lower than the "agronomic optimum" yield population. Use the calculator above to estimate the cost per acre based on bag price.

Calculating Linear Feet Per Acre

Accurate calibration depends on knowing the total linear feet of row in one acre. An acre contains 43,560 square feet.

Formula: 43,560 ÷ (Row Width in inches ÷ 12)

For a standard 30-inch row, there are 17,424 linear feet of row per acre. This metric is constant for the row width and is essential for ground-truthing your planter's performance in the field.