1. Measure the controlling geometry
Room modes use room, furniture, bed, table, or hallway measurements. Custom Shape mode uses the dimensions that uniquely define the selected geometry instead of guessing from area alone.
Rug Size Calculator
Plan rug dimensions for rooms, furniture layouts, runners, and simple custom-cut shapes.
Choose a room scenario for everyday sizing or Custom Shape for circles, ellipses, triangles, trapezoids, circular segments, and curved-end rugs.
Region & Unit
US offers inches or feet. Canada offers centimetres or metres.
Changing region or unit clears measurements so values from different units are not mixed.
Choose a Rug Planning Mode
Pick the room or custom geometry that matches what you are measuring.
Room Measurements
Measure the rectangular room, then choose how much exposed floor you want around the rug.
Available Rug Sizes
Optional. Compare the calculated ideal size with actual sizes you can buy.
Rug Pad
Optional for rectangle, square, round, and ellipse results.
Results update automatically when all required measurements are complete.
Your rug sizing plan
Choose a planning mode and enter the required measurements. No sample measurements are inserted.
Planning disclaimer: This rug sizing result is a planning estimate based on the measurements and geometric model you enter. Confirm actual room conditions, furniture placement, product dimensions, rug orientation, and custom-cut measurements before ordering or cutting a rug.
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How the Rug Size Calculator Works
The calculator uses the measurements that define your room, furniture layout, runner, or custom shape. It first resolves the ideal rug geometry, then optionally compares that result with the stock sizes you enter and calculates a smaller rug pad where the selected shape supports it.
2. Calculate the rug dimensions
Borders, extensions, overhangs, and chair clearance are applied exactly as entered. For custom shapes, the calculator also returns the bounding dimensions, area, and measurable edge information.
3. Resolve simple curved edges
A circular segment is defined by chord width and arc depth. A half ellipse is defined by overall width and arc depth. These inputs are intended to be measurable on site without asking the user to find a circle center or ellipse focus.
4. Compare available rug sizes
Minimum Sufficient finds the smallest entered size that meets the required bounding dimensions. Closest Fit can return a nearer option even when it is not fully sufficient, and the result is labeled accordingly.
Formula
General room
Rug width = room width − 2 × side border
Rug length = room length − 2 × end border
Living room — all legs / front legs
Rug width = measured anchor width + 2 × side extension
Rug depth = measured anchor depth + front extension + back extension
Living room — floating
Rug width = open area width − 2 × side clearance
Rug depth = open area depth − 2 × end clearance
Hallway runner
Runner width = hallway width − 2 × side border
Runner length = hallway length − 2 × end border
Basic custom shapes
Rectangle area = width × length
Square area = side²
Round area = π × (diameter ÷ 2)²
Ellipse area = π × (width ÷ 2) × (length ÷ 2)
Bedroom
Rug width = bed width + 2 × side overhang
Rug length = bed length + foot overhang
Dining room
Rectangle: table dimensions + 2 × chair clearance
Round: table diameter + 2 × chair clearance
Triangle
Area = base × perpendicular height ÷ 2
Side lengths use the measured apex offset and Pythagorean distance.
Trapezoid
Area = (top width + bottom width) × height ÷ 2
Top-left offset determines the two sloped sides and true bounding width.
Circular segment
Radius = c² ÷ (8h) + h ÷ 2
Center angle = 4 × atan(2h ÷ c)
Arc length = radius × center angle
Half ellipse
a = overall width ÷ 2; b = arc depth
Area = πab ÷ 2
Curved edge length is an approximation, not an exact ellipse perimeter.
Minimum sufficient stock size
A candidate must meet both required bounding dimensions.
When rotation is allowed, width and length are also tested after a 90° rotation.
Among sufficient candidates, the calculator prefers the smallest qualifying area, then smaller excess dimensions.
Closest fit
Each allowed orientation is scored from its proportional width and length differences.
A closest result can still be undersized and is labeled as such.
Rectangle + curved end
Total area = rectangle area + circular-segment or half-ellipse area
Overall length = straight section length + curved depth
The internal chord is not counted as an outside perimeter edge.
Rug pad
Pad width/diameter = rug dimension − 2 × inset
Complex custom-shape offset curves are not estimated.
How to Measure Curved Rug Shapes
Curved custom rugs are only useful when the measurements describe the actual curve. The calculator therefore asks for dimensions that can be measured directly rather than for a hidden radius or center point.
Circular segment
Measure the chord width as a straight line between the two points where the curve begins. From the midpoint of that line, measure perpendicular to the furthest point of the curve for the arc depth. Do not measure along the curved edge.
This calculator models a minor circular segment only, so arc depth must be no more than half the chord width.
Half ellipse
Measure the overall width straight across the two points where the curve begins. Then measure from the midpoint of that line to the furthest point of the curve for the arc depth.
Use this mode only when the boundary is reasonably approximated by a half ellipse. A wave, S-curve, or several connected arcs requires a physical template or professional measurement.
Rug Size by Room
Use these as measurement starting points, not fixed design rules. The calculator always uses your actual dimensions, borders, overhangs, and clearances.
| Room / layout | What to measure | How the calculator sizes the rug |
|---|---|---|
| Living room — all legs | Full furniture footprint + desired extensions | Measured footprint plus the entered side, front, and back extensions |
| Living room — front legs | Front-leg anchor footprint + desired extensions | Front-leg anchor plus the extensions you enter |
| Living room — floating | Open area width/depth + edge clearances | Open area minus the entered clearances |
| Bedroom | Bed width/length + side and foot overhang | Bed width + both side overhangs; bed length + foot overhang |
| Queen / King bed | Queen preset 60 × 80 in; King preset 76 × 80 in, both editable | Adds your chosen overhang before comparing with stock sizes such as 8 × 10 or 9 × 12 ft |
| Dining room | Table dimensions + chair clearance | Adds the entered clearance around the table footprint |
| Hallway / runner | Hallway width/length + side/end borders | Subtracts the entered exposed-floor borders |
Common Rug Sizes to Compare
These are common comparison sizes for shopping, not automatic recommendations. Enter the sizes actually offered by the product you are considering and let the matcher compare them with your calculated requirement.
| Feet | Approx. centimetres |
|---|---|
| 4 × 6 ft | 121.92 × 182.88 cm |
| 5 × 8 ft | 152.4 × 243.84 cm |
| 6 × 9 ft | 182.88 × 274.32 cm |
| 8 × 10 ft | 243.84 × 304.8 cm |
| 9 × 12 ft | 274.32 × 365.76 cm |
| 10 × 14 ft | 304.8 × 426.72 cm |
When to Use This Calculator
- • Plan a rug while keeping a chosen border of exposed floor.
- • Size a living-room rug around measured furniture positions.
- • Plan bedroom overhang around a bed footprint.
- • Add chair clearance around a dining table.
- • Calculate hallway or runner dimensions.
- • Calculate measurable triangle or trapezoid custom-cut dimensions.
- • Size a single circular or half-ellipse curved edge.
- • Compare an ideal result with actual rug sizes available to buy.
Worked Examples
These examples use the same calculation rules as the interactive calculator, so the displayed results stay consistent with the current calculation rules.
12 ft × 15 ft room
A rectangular room is 12 ft wide by 15 ft long. The plan keeps 1 ft of exposed floor along each side and at each end.
- Calculated rug width
- 10 ft
- Calculated rug length
- 13 ft
- Area
- 130 ft²
60 in chord with 12 in arc depth
A custom curved edge has a 60 in straight chord and a 12 in perpendicular depth at the midpoint.
- Radius
- 43.5 in
- Arc length
- 66.21 in
- Segment area
- 495.03 in²
Methodology and Planning Guidance
Room and furniture placement conventions are useful starting points, but they are not treated as universal design rules here. The calculator uses the dimensions, borders, extensions, overhangs, clearances, and stock sizes that you enter.
Standard stock dimensions are comparison sizes only. For custom cutting, the geometry must match the real site condition: a circular mode assumes one minor circular segment, and a half-ellipse mode assumes one half ellipse. Recheck custom curves with a physical template or installer when the edge is irregular.
Assumptions and Limitations
Room and furniture modes are planning models driven by the dimensions, borders, extensions, and clearances you enter. The calculator does not claim that one border, overhang, or chair clearance is universally correct for every home or product.
Custom curved modes assume the measured edge follows one minor circle segment or one half ellipse. This calculator does not model major circular arcs, S-shaped or wave-shaped edges, multiple connected arcs, arbitrary polygons, CAD drawings, construction templates, fabric yardage, binding allowance, pattern repeat, or automatic site-error compensation.
Available-size matching uses only the stock dimensions you enter. Rug-pad calculations are limited to supported regular shapes; ellipse pad dimensions reduce the two axes and are not a true uniform geometric offset.
Measurement Review Before You Order or Cut
Recheck the actual room edges, furniture positions, product orientation, and manufacturer dimensions before buying. For a custom curved rug, verify the curve with a physical template whenever the wall or floor edge is not clearly one circular segment or half ellipse. Complex wave-shaped or multi-arc conditions should be professionally measured.
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Rug Size Calculator FAQ
How do I choose the right area rug size for a room?
Measure the usable room width and length, then decide how much exposed floor you want around the rug. General Room mode subtracts the side and end borders you enter instead of assuming one universal rug-to-wall spacing.
Should living-room furniture have all legs or front legs on the rug?
Either layout can work, but the measurements are different. Use All Legs On when the full furniture footprint should sit on the rug, Front Legs On when the front-leg anchor area controls the placement, or Floating when the rug sits inside a measured open area. The calculator uses the layout and extensions you enter.
What size rug should go under a queen or king bed?
There is no single required stock size because the answer depends on the side and foot overhang you want. The calculator starts with the bed dimensions—its Queen preset is 60 × 80 in and King preset is 76 × 80 in—then adds your chosen overhang. You can compare the result with common 8 × 10 ft or 9 × 12 ft stock sizes without treating either as an automatic recommendation.
What size rug should go under a dining table?
Enter the table dimensions and the chair clearance you want beyond each table edge. The calculator adds that clearance on both sides of rectangular or square tables, or around the diameter of a round table, so chairs can be planned from your actual measurements rather than a fixed universal allowance.
How wide should a hallway runner be?
Measure the hallway width and choose the exposed floor border you want on each side. The calculator subtracts twice that side border to get the runner width, and uses the hallway length minus twice the entered end border for runner length.
How do I measure a circular or half-ellipse edge for a custom rug?
For a circular segment, measure the straight chord between the two points where the curve begins, then measure perpendicular from the chord midpoint to the furthest point of the curve. For a half ellipse, measure the overall width across the curve start points and the same midpoint-to-curve depth. The calculator supports one minor circular segment or one half ellipse, not a multi-arc wave.
How does the available rug size matcher work?
Minimum Sufficient selects the smallest entered stock size that meets both required bounding dimensions, with 90-degree rotation considered when enabled. Closest Fit can return a nearer size even when it is undersized, and the result is labeled so it is not mistaken for a sufficient fit.
Can this calculator handle irregular or wave-shaped rooms?
Not as one automatic freeform shape. This calculator supports defined geometry such as triangles, trapezoids, one minor circular segment, one half ellipse, and rectangle-plus-curved-end shapes. Multi-arc, S-shaped, freeform, or uneven site conditions should be templated or professionally measured before custom cutting.