Calculate the exact number of plants needed for your garden or farm layout.
Square/Grid Layout
Triangular (Offset) Layout
Total Plants Required:
0
How to Use the Plant Spacing Calculator
Planning your garden layout is critical for maximizing yield and maintaining plant health. This tool helps you determine exactly how many seedlings or seeds you need based on your available garden real estate.
Square vs. Triangular Layouts
Square Layout: Plants are placed in straight rows and columns, creating a grid. This is the easiest for weeding and mechanical cultivation. However, it leaves more bare soil exposed.
Triangular Layout: Also known as hexagonal spacing or offset planting. Plants in every other row are shifted by half the spacing distance. This is the most efficient use of space, allowing for approximately 15% more plants in the same area compared to square grids, while providing better ground cover to suppress weeds.
Common Vegetable Spacing Guide
Plant Type
Spacing (Inches)
Carrots / Onions
3″ – 4″
Lettuce / Spinach
6″ – 10″
Bush Beans
4″ – 6″
Kale / Chard
12″ – 18″
Peppers / Eggplant
18″ – 24″
Tomatoes
24″ – 36″
Practical Example
If you have a raised bed that is 8 feet long and 4 feet wide, and you want to plant kale spaced at 12 inches apart:
Square Layout: You would fit 8 plants along the length and 4 along the width, totaling 32 plants.
Triangular Layout: By offsetting the rows, you utilize the gaps, allowing you to fit roughly 37 plants in the same 32 square foot space.
function calculatePlants() {
var lengthFt = parseFloat(document.getElementById('areaLength').value);
var widthFt = parseFloat(document.getElementById('areaWidth').value);
var spacingIn = parseFloat(document.getElementById('plantSpacing').value);
var pattern = document.getElementById('plantingPattern').value;
if (isNaN(lengthFt) || isNaN(widthFt) || isNaN(spacingIn) || spacingIn <= 0 || lengthFt <= 0 || widthFt <= 0) {
alert("Please enter valid positive numbers for all fields.");
return;
}
var lengthIn = lengthFt * 12;
var widthIn = widthFt * 12;
var totalPlants = 0;
var totalArea = lengthFt * widthFt;
if (pattern === 'square') {
// Simple grid calculation
var plantsWide = Math.floor(widthIn / spacingIn);
var plantsLong = Math.floor(lengthIn / spacingIn);
// If they fit at the very edges, we add 1 to each dimension
// (e.g. 12 inch bed with 12 inch spacing fits 2 plants: 0" and 12")
// But usually, we leave a small buffer. Using standard garden math:
plantsWide = Math.floor(widthIn / spacingIn) + 1;
plantsLong = Math.floor(lengthIn / spacingIn) + 1;
totalPlants = plantsWide * plantsLong;
} else {
// Triangular spacing math: Area / (Spacing^2 * sin(60deg))
// sin(60) is approx 0.866
// This is the theoretical density. For small gardens, we use a row-by-row calc
var rowHeight = spacingIn * 0.866;
var numRows = Math.floor(widthIn / rowHeight) + 1;
var plantsPerRow = Math.floor(lengthIn / spacingIn) + 1;
var plantsPerOffsetRow = Math.floor((lengthIn – (spacingIn / 2)) / spacingIn) + 1;
var fullRows = Math.ceil(numRows / 2);
var offsetRows = Math.floor(numRows / 2);
totalPlants = (fullRows * plantsPerRow) + (offsetRows * plantsPerOffsetRow);
}
document.getElementById('plantResultBox').style.display = 'block';
document.getElementById('totalPlants').innerText = Math.round(totalPlants) + " Plants";
var density = (totalPlants / totalArea).toFixed(2);
document.getElementById('coverageDetails').innerText = "For a " + totalArea + " sq. ft. area, your planting density is approximately " + density + " plants per square foot.";
}