UNIT SYSTEM // RSA
SOUTH AFRICAN
SURVEY UNIT CONVERTER
Morgen, Cape feet and the measurements on older survey records. Select the unit as written on your record, then convert.
WHAT DOES THAT LOOK LIKE?
Enter a positive value to see useful real-world comparisons.
Comparison assumptions
References are approximate and are intended to communicate scale—not survey accuracy.
OLD SOUTH AFRICAN SURVEY UNITS
Older South African survey diagrams and land records may contain morgen, Cape feet, Geodetic Cape feet, Cape roods and South African Geodetic feet. This South African land area and length converter provides a quick reference to metric and imperial measurements.
The Cape foot was used in historical land measurement. A Cape rood is 12 Cape feet, and the Cape morgen was historically defined as 600 square Cape roods. For morgen to hectare or morgen to square metres conversions, this tool uses the prescribed area factor, not a reconstruction from rounded historical lengths.
Geodetic surveys also used Geodetic Cape feet and South African Geodetic feet. A Cape foot to metre conversion is therefore not interchangeable with a Geodetic Cape foot to metre conversion. Check the unit before using a number from an old SG diagram.
Historical reference: Download: The South African measurement system and its origin (PDF, 54 KB). Written by Tomasz Zakiewicz of Chief Directorate: National Geo-spatial Information; published in PositionIT, April/May 2011, pages 29–31. Original article recovered from the Internet Archive.
CONVERSION BASIS / VIEW ALL FACTORS
Calculations pass through metres or square metres using the constants below. Morgen, acre and the two geodetic foot factors follow CSG Land Survey Regulations, regulation 3 (PDF). The remaining historical and imperial factors follow NGI Table 1 — download the original article (PDF, 54 KB); metric multiples use their standard definitions.
Basis matters: Acre uses the South African survey factor of 4,046.86 m². Square mile uses NGI's rounded 2,589,988 m². These area factors are not presented as exact areas derived from the international foot. The Geodetic Cape rood retains NGI's published 3.7782669 m factor. Extra output digits do not add precision to a published factor.
| Morgen | 8565.32 |
|---|---|
| Hectare (ha) | 10000 |
| Square metre (m²) | 1 |
| Square kilometre (km²) | 1000000 |
| Acre (SA survey basis) | 4046.86 |
| Square foot (ft²) | 0.09290304 |
| Square yard (yd²) | 0.83612736 |
| Square mile (NGI rounded) | 2589988 |
| Cape foot | 0.3148581 |
|---|---|
| Geodetic Cape foot | 0.31485557516 |
| South African Geodetic foot | 0.3047972654 |
| Cape rood | 3.7782972 |
| Geodetic Cape rood | 3.7782669 |
| Millimetre (mm) | 0.001 |
| Metre (m) | 1 |
| Kilometre (km) | 1000 |
| Foot (international) | 0.3048 |
| Yard (yd) | 0.9144 |
| Mile (mi) | 1609.344 |
A FEW USEFUL ANSWERS
How many hectares are in one morgen?
One morgen is 0.856532 hectares using the South African survey conversion factor. To convert hectare to morgen, divide the hectare value by 0.856532.
How many square metres are in one morgen?
One morgen is 8,565.32 m². Multiply a morgen value by 8,565.32 to obtain square metres.
Is a Cape foot the same as a normal foot?
No. A Cape foot is 0.3148581 m; an international foot is 0.3048 m. A Geodetic Cape foot is different again, at 0.31485557516 m.
What is a South African Geodetic foot?
It is a historical South African geodetic survey unit. This tool uses 0.3047972654 m per South African Geodetic foot, distinct from both Cape foot variants and the international foot.
Why do old South African survey diagrams use different units?
Survey records reflect different periods, regional practices and geodetic standards. Similar names do not guarantee identical values. Check the original record and its conversion basis before interpreting an older measurement.
How big is 2.5 acres?
Using the South African survey conversion factor in this calculator, 2.5 acres is 10,117.15 m² or 1.011715 hectares. For scale, that is about 1.4 reference soccer pitches at 105 × 68 m, or roughly ten 1,000 m² reference plots.
What does 150 metres look like?
150 metres is 492.126 international feet or 0.15 kilometres. It is about 1.5 rugby field-of-play lengths, or roughly a two-minute brisk walk using a reference pace of 1.25 m/s.