Formula Used
Irregular polygon: P = s₁ + s₂ + s₃ + ... + sₙ
Regular polygon: P = n × s
Coordinate side: d = √((x₂ − x₁)² + (y₂ − y₁)²)
The perimeter equals the total length around a polygon. Add every boundary side once. Coordinate mode calculates each connecting distance before summing.
How to Use the Calculator
- Select the calculation mode that matches your available data.
- Choose the input and primary result measurement units.
- Enter side lengths, regular dimensions, presets, or coordinates.
- Select the required decimal precision for displayed answers.
- Press Calculate Perimeter and review every result section.
- Copy, print, or download the calculation when required.
Example Data
| Polygon | Inputs | Perimeter |
|---|---|---|
| Triangle | 3 m, 4 m, 5 m | 12 m |
| Rectangle | 8 m, 5 m, 8 m, 5 m | 26 m |
| Regular Pentagon | 5 sides × 6 cm | 30 cm |
| Irregular Hexagon | 2, 3, 4, 5, 6, 7 ft | 27 ft |
| Coordinate Square | (0,0), (4,0), (4,4), (0,4) | 16 units |
Frequently Asked Questions
What is a polygon perimeter?
A polygon perimeter is its complete outside boundary length. It includes every side exactly once. The result uses linear measurement units.
How is an irregular polygon measured?
Measure every side of the irregular polygon carefully. Add all measured values together. Keep every length in matching units.
How is a regular polygon measured?
A regular polygon has equal side lengths. Multiply one side by the side count. This gives the complete perimeter directly.
Can fractions be entered?
Yes, the calculator accepts decimal and fractional values. Mixed values like 3 1/2 also work. All entered lengths must remain positive.
How does coordinate mode work?
Coordinate mode joins vertices in their entered order. It calculates each side using distance. The final vertex reconnects automatically.
Can different units be converted?
Yes, select one input unit first. Then choose any primary result unit. The conversion table shows additional supported units.
Does perimeter include area?
No, perimeter measures only the outside boundary. Area measures the enclosed two-dimensional region. Their units and formulas remain different.
Why must a polygon have three sides?
A closed polygon requires at least three segments. Two segments cannot enclose a region. Therefore, three sides form the minimum.
What causes invalid coordinate results?
Repeated points can create zero-length sides. Missing values also prevent valid distance calculations. Enter unique and complete coordinate pairs.