DMS to Decimal Degrees 変換ツール
Convert Degrees, Minutes, and Seconds to Decimal format. Required for digitizing historic deed descriptions and survey records.
Quick Reference
DMS Formula: Decimal = Degrees + (Minutes ÷ 60) + (Seconds ÷ 3600)
Example: 4026'47"N = 40 + (26/60) + (47/3600) = 40.446944N
Pro Tip: Always verify hemisphere direction (N/S, E/W)—sign errors cause 180 positional mistakes.
度分秒 → 十進法度数 変換テーブル
Common DMS values and their decimal equivalents. Use this table for quick reference or verify your conversion results.
| DMS Input | Decimal Degrees | Description |
|---|---|---|
| 0 0' 1" | 0.000278 | One arc-second (~31 meters at equator) |
| 0 1' 0" | 0.016667 | One arc-minute (~1.85 km at equator) |
| 0 30' 0" | 0.500000 | Half a degree (~55.5 km at equator) |
| 1 0' 0" | 1.000000 | One degree (~111 km at equator) |
| 33 51' 54" | 33.865000 | Los Angeles, CA (latitude) |
| 35 41' 22.4" | 35.689556 | Tokyo, Japan (latitude) |
| 40 44' 55.7" | 40.748806 | Empire State Building, NYC (latitude) |
| 48 51' 24" | 48.856667 | Eiffel Tower, Paris (latitude) |
| 51 28' 38" | 51.477222 | Greenwich Observatory, London (latitude) |
| 90 0' 0" | 90.000000 | North Pole |
Related Coordinate Conversion ツール一覧
よくあるご質問 (FAQ)
What is DMS format and why is it used?
DMS (度・分・秒) is the traditional format for expressing coordinates, inherited from maritime navigation. 1 degree = 60 minutes; 1 minute = 60 seconds. Professional surveyors and historical deed descriptions use DMS because it's human-readable and represents historical measurements from surveying instruments (theodolites, transits).
How many decimal places do I need for accuracy?
6 decimal places: 0.11m precision (professional standard). 5 decimal places: 1.1m precision (acceptable for GIS). 4 decimal places: 11m precision (land survey only with caution). Less than 4: Not acceptable for professional use.
What does N/S and E/W mean, and why is it critical?
N = North (positive latitude), S = South (negative). E = East (positive longitude), W = West (negative). Misinterpreting hemisphere causes a sign flip, placing coordinates 180 away. A fence built using the wrong hemisphere notation could end up on the opposite side of the Earth.
DDM vs DMS, what's the difference?
DDM (Decimal Degrees Minutes) is 4026.7867', while DMS is 4026'47.04". DDM is a hybrid format used by some GPS receivers. This tool converts DMS to pure decimal degrees (DD), the standard for GIS and professional mapping systems.
地殻変動と再施工リスク：NAD83 vs WGS84の累積誤差
北米プレートは年間約2cm移動するため、NAD83(2011)とWGS84(G1762)は現在2.2メートル以上乖離しています。 高精度なNAD83地籍杭打ちに「標準的な」GPS WGS84座標を使用したことで、基礎のやり直しやインフラの配置ミスによる5万ドルの専門家責任賠償請求が発生しています。