How to Use a Drafting Scale


When making architectural drawings of a structure, a draftsman must determine a "scale" for the drawings so that they reflect the building's correct proportions. For example, a drawing might be executed at 1/4" scale so that 1 foot in the actual building is drawn at 1/4" in the drawing. The drafting scale is a special type of ruler that helps drafting professionals create their scale drawings accurately. Shaped like a pyramid, the drafting scale contains two different measurements on each face--one beginning at each end. Each set of measuring increments represents a different proportional scale (e.g., 1/4", 1/8", 3/16"). The increments in each set are numbered according to the desired measurements of the completed drawing. So, if a draftsman needs to draw a line 4 feet long at 1/4" scale, he will choose the 1/4" measuring side of the drafting scale and draw his line from "0" to the tick mark labeled "4". This tool allows a draftsman to easily create drawings at the appropriate scale without needing to actually calculate the proportional ratio. It is particularly helpful in changing the proportions of drawings required for a project. Here's how to use a drafting scale to measure one floor plan drawing and create a new one at a different scale.

Things You'll Need

  • Floor plan drawn to scale Straight edge Pencil
  • Find the scale of your original drawing. It may be included in the drawing legend. If the legend does not indicate the measuring ratio, you can use an architectural element with a standard measurement, such as a window or doorway, to determine the scale by trial and error. For example, typical exterior doorways are 3 feet wide. When you locate one on your original floor plan, measure it with various sides of your drafting scale to determine which one indicates "3" for the width of the door opening. Then, look at the left end of your drafting scale on that face to find the correct proportional scale.

  • Decide on a scale for your resized floor plan. You can enlarge or reduce the proportions of your original drawing according to your project needs. Check each end of your drafting scale until you locate the desired measuring ratio.

  • Choose a starting point for your new drawing. A corner of the original drawing is a good place to begin. You will be able to create your new floor plan by measuring one line at a time on the original and drawing it at the new proportional scale on the revised floor plan.

  • Measure your original drawing at the starting point. Locate the side of your drafting scale that measures dimensions based on the original floor plan's proportional scale. Then, line up "0" at the corner of your starting point. Check the tick marks on the drafting scale to determine the length of the first horizontal line in your original drawing.

  • Create your first line on the new floor plan. With a straight edge, draw a horizontal line of any length. Then, flip your drafting scale until it shows the chosen scale for your new drawing, with "0" at the left. Line up the straight edge of the drafting scale with the horizontal line you drew. Make a light mark with your pencil at the "0" tick mark and at the tick mark of the dimension of the original floor plan's first horizontal line (determined in Step 4). Now you have your newly scaled starting point for your revised floor plan. Erase any unneeded portions of the horizontal line.

  • Draw in additional lines on your new floor plan. Working up and out on your original floor plan, continue to measure the first drawing line by line, drawing the corresponding lines on the new floor plan using the appropriate measuring scale. Once all of your lines are in place, you can erase any stray lines and ink in the new drawing as needed.

Tips & Warnings

  • Create your drawing in pencil first to make measuring errors easier to correct. You can ink it in when complete. Use a small drafting dot or sticker to mark the starting end of your chosen measuring scale. That way, it's easy to flip straight to the increments you need. Be sure to include a scale legend on your new drawing so it is easy to determine the new size.
  • Don't make a practice of using your drafting scale as a straight edge for drawing. This will wear away the markings and shorten the life of your scale.

Related Searches

Promoted By Zergnet


You May Also Like

  • How to Use a Three-Sided Drafter's Ruler

    How to Use a Three-Sided Drafter's Ruler. The drafter's ruler (also called an architect's scale) has three sides with one or two...

  • How to Use Drafting Tools

    Drafting tools are an architect's best friend. You can't begin to apply your advanced drafting skills until you've learned how to select...

  • What Is the Pay Scale for NFL Draft Picks?

    Players drafted in the NFL Draft earn lucrative contracts, but the dollar amounts pale in comparison to the contracts awarded before 2011.

  • Types of Drawing Scales

    A scale is a ruler that is used for measurement in drawing. Different scales are made for specific measurement use in engineering,...

  • Mechanical Drawing Tools

    Mechanical drawing refers to the process of drawing plans for manufactured goods. Someone who engages in drawing is called a draftsman. Mechanical...

Related Searches

Check It Out

12 Tiki Essentials to Turn Your Bar Cart Into a Tropical Paradise

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!