function calculateTableSize() {
var guests = parseInt(document.getElementById('numPeople').value);
var shape = document.getElementById('tableShape').value;
var rLen = parseFloat(document.getElementById('roomLength').value) * 12; // Convert to inches
var rWid = parseFloat(document.getElementById('roomWidth').value) * 12; // Convert to inches
var resultDiv = document.getElementById('tableResult');
var sizeOut = document.getElementById('sizeOutput');
var clearOut = document.getElementById('clearanceOutput');
var warning = document.getElementById('roomWarning');
resultDiv.style.display = 'block';
warning.style.display = 'none';
var recLength = 0;
var recWidth = 0;
var recDia = 0;
var displayStr = "";
// Standard Clearance Rule: 36 inches per side for chairs/traffic
var maxTableLen = rLen – 72;
var maxTableWid = rWid – 72;
if (shape === 'rectangular') {
// Rule of thumb: 24 inches per person minimum
if (guests <= 4) {
recLength = 48; recWidth = 36;
} else if (guests <= 6) {
recLength = 72; recWidth = 36;
} else if (guests <= 8) {
recLength = 96; recWidth = 42;
} else if (guests maxTableLen || recWidth > maxTableWid) {
warning.innerText = "Warning: This table may be too large for your room dimensions. A 3-foot clearance is recommended around all sides.";
warning.style.display = 'block';
}
} else if (shape === 'round') {
if (guests <= 4) recDia = 42;
else if (guests <= 6) recDia = 54;
else if (guests <= 8) recDia = 66;
else if (guests maxTableLen || recDia > maxTableWid) {
warning.innerText = "Warning: This diameter exceeds the comfortable capacity for your room width/length.";
warning.style.display = 'block';
}
} else if (shape === 'square') {
if (guests <= 4) recLength = 36;
else if (guests maxTableLen || recLength > maxTableWid) {
warning.innerText = "Warning: A square table of this size requires a much larger room for proper clearance.";
warning.style.display = 'block';
}
}
sizeOut.innerText = displayStr;
clearOut.innerText = "Based on " + guests + " guests. Industry standard: 24-30 inches of width per person.";
}
How to Choose the Perfect Dining Table Size
Choosing a dining table isn't just about how many people you can squeeze around it; it's about the "golden ratio" of comfort, traffic flow, and room aesthetics. Our dining room table size calculator uses industry-standard ergonomics to help you find the sweet spot for your specific space.
The Rule of 36 Inches
The most important number in dining room design is 36 inches (3 feet). This is the minimum amount of space required between the edge of the table and the wall or any other furniture (like a sideboard). This allows for:
Space to pull a chair out comfortably.
Room for a person to walk behind someone who is already seated.
A balanced look that doesn't make the room feel cramped.
Seating Capacity Guidelines
When calculating for guests, consider that each person needs a "place setting" area. A comfortable standard is 24 inches of width per person. However, for a more formal or "elbow-room" friendly experience, 30 inches is preferred.
Shape
4 People
6 People
8 People
Rectangular
48″ Long
60″ – 72″ Long
78″ – 96″ Long
Round
36″ – 44″ Dia
48″ – 54″ Dia
60″ – 72″ Dia
Example Calculation
Suppose you have a dining room that is 12 feet by 10 feet. To find your maximum table size:
Subtract 6 feet (3ft each side) from the length: 12′ – 6′ = 6 feet (72 inches).
Subtract 6 feet from the width: 10′ – 6′ = 4 feet (48 inches).
Your ideal maximum table size for this room is 72″ x 48″.
Always remember to account for rugs; if you use a rug under the table, it should be at least 24-30 inches wider than the table on all sides so the chair legs don't get caught on the edge when pulled out.