Calculate real-world sizes from a 1/8″ = 1′-0″ scale drawing, or convert real measurements to scale, with this 1:96 architectural scale calculator.
1/8″ = 1′-0″ Scale Formula
This calculator works with the architectural scale where 1/8 inch on the drawing represents 1 foot in real life. That is a scale factor of 1:96, because one real foot is 12 inches and 12 divided by 1/8 equals 96.
To convert a measurement taken from the drawing into a real-world size:
Real (ft) = Drawing (in) * 8
To convert a real-world size into the length you should draw:
Drawing (in) = Real (ft) / 8
If you switch to another architectural scale, the calculator uses the general form, where SF is the scale factor (96 for 1/8″ = 1′-0″):
Real (ft) = Drawing (in) * SF / 12
- Real (ft): the actual real-world length, in feet.
- Drawing (in): the length measured on the drawing, in inches.
- SF: the scale factor of the drawing. For 1/8″ = 1′-0″ it is 96.
- 8: the number of real feet represented by one inch on a 1/8″ = 1′-0″ drawing.
The “Solve for” selector chooses the direction. Pick “Drawing measurement to Real size” when you measured something on a plan and want its true size. Pick “Real size to Drawing measurement” when you know the real size and want to know how long to draw it. The optional scale selector lets you apply the same math to other common architectural scales such as 1/4″ = 1′-0″ or 1/2″ = 1′-0″.
Common Architectural Scales and Their Factors
Each architectural scale has a fixed scale factor and a fixed number of real feet per drawing inch. The 1/8″ = 1′-0″ row is the default used by this calculator.
| Scale | Scale factor | Real feet per drawing inch |
|---|---|---|
| 1/16″ = 1′-0″ | 1:192 | 16 ft |
| 1/8″ = 1′-0″ | 1:96 | 8 ft |
| 1/4″ = 1′-0″ | 1:48 | 4 ft |
| 1/2″ = 1′-0″ | 1:24 | 2 ft |
| 1″ = 1′-0″ | 1:12 | 1 ft |
Quick 1/8″ = 1′-0″ Conversions
These are common drawing measurements and the real sizes they represent at 1/8″ = 1′-0″.
| Drawing measurement | Real size |
|---|---|
| 1/8 in | 1 ft |
| 1/2 in | 4 ft |
| 1 in | 8 ft |
| 2 in | 16 ft |
| 3 1/8 in | 25 ft |
Example Problems
Example 1. You measure a wall on a floor plan and it is 2.5 inches long. The plan is drawn at 1/8″ = 1′-0″. Multiply the drawing inches by 8: 2.5 times 8 equals 20. The wall is 20 feet long in real life.
Example 2. A room is 10 feet 6 inches wide and you want to draw it at 1/8″ = 1′-0″. First convert to feet: 10 feet 6 inches is 10.5 feet. Divide by 8: 10.5 divided by 8 equals 1.3125 inches. You draw the room 1 5/16 inches wide.
Frequently Asked Questions
What scale factor is 1/8″ = 1′-0″?
It is 1:96. One unit on the drawing equals 96 of the same units in real life. You can see this because one real foot is 12 inches, and 12 divided by 1/8 inch equals 96.
How many feet does one inch represent at 1/8″ = 1′-0″?
One inch on the drawing represents 8 feet. Since 1/8 inch equals 1 foot, a full inch is eight of those 1/8 inch steps, so it equals 8 feet.
Can I use this calculator for other architectural scales?
Yes. Check the box to use a different scale and pick one from the list, such as 1/4″ = 1′-0″ or 1/2″ = 1′-0″. The calculator applies the matching scale factor to both conversion directions.
