Convert Hectare to Square Decimeter
Convert hectares to square decimeters instantly. 1 hectare = 1000000 square decimeter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Decimeter to Hectare converter for the reverse conversion.
Units explained
Hectare
A hectare is a metric unit of area equal to 10,000 square meters, or one square hectometer. It is the most widely used metric unit for land measurement worldwide.
Defined as 100 ares, equal to one square hectometer. The name was introduced in 1795 in France as part of the metric system.
Hectares are the standard unit for agricultural land measurement worldwide except in the US (which uses acres). 1 hectare equals 2.47105 acres. In India, hectares are used in modern agricultural census and land records alongside traditional regional units.
Adopted in France in 1795; standardized internationally through the SI system.
Square Decimeter
A square decimeter is a metric unit of area equal to 0.01 m². It is rarely used in everyday measurement but exists for SI completeness and appears in some scientific contexts.
Derived by squaring the decimeter (1/10 of a meter). The deci- prefix comes from the Latin 'decimus' (tenth).
Square decimeters appear in some scientific contexts and in regions where the decimeter itself is used. Most everyday applications would use cm² or m² instead.
Decimeter has been part of the metric system since 1795.
Hectare to Square Decimeter conversion formula
The relationship between hectares and square decimeters:
To convert hectares to square decimeters, multiply the value in hectares by 1000000. To reverse, multiply square decimeters by 1e-6.
How to use this converter
Type a value into the calculator. The result in square decimeters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Square Decimeter to Hectare converter for the reverse direction.
Step-by-step: convert hectares to square decimeters
- Write down the value in hectares (ha).
- Multiply that value by the factor 1000000.
- The product is the equivalent value in square decimeters (dm²).
- To reverse, multiply the square decimeter value by 1e-6.
Worked examples
Example 1 — Convert 1 ha to dm²:
1 × 1000000 = 1000000 dm²
Example 2 — Convert 100 ha to dm²:
100 × 1000000 = 1e+8 dm²
Real-world example — Geographic to architectural conversion
One hectare equals 100,000 square decimeters. The conversion bridges geographic-scale survey work and architectural-scale building plans on the same drawing.
1 ha × 1000000 = 1000000 dm²
Real-world example — Geographic to architectural scale
One hectare equals 100,000 square decimeters. Map scales use this when an architectural site plan (in the smaller unit) must be related to road-network plans (in the larger unit) on the same drawing.
1 ha × 1000000 = 1000000 dm²
Hectare to Square Decimeter conversion table
Standard reference values for converting hectares to square decimeters:
| Hectare [ha] | Square Decimeter [dm²] |
|---|---|
| 0.01 | 10000 |
| 0.1 | 100000 |
| 1 | 1000000 |
| 2 | 2000000 |
| 3 | 3000000 |
| 4 | 4000000 |
| 5 | 5000000 |
| 10 | 1e+7 |
| 20 | 2e+7 |
| 30 | 3e+7 |
| 40 | 4e+7 |
| 50 | 5e+7 |
| 100 | 1e+8 |
| 500 | 5e+8 |
| 1000 | 1e+9 |
Frequently asked questions
How many square decimeters is 1 hectare?
How do I convert hectares to square decimeters?
How do I convert square decimeters back to hectares?
How many square decimeters is 100 hectares?
Popular area unit conversions
Convert Hectare to other area units
Show all Hectare conversions
Metric / SI (15 units)
Imperial / US Customary (15 units)
US Survey (5 units)
Indian Subcontinent (16 units)
Other Regional (10 units)
Scientific / Physics (5 units)
Historical / Pre-metric European (6 units)
Sources & references
Conversion factor (1 ha = 1000000 dm²) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.