Sewing 207 - Pattern Drafting: The Basic Trouser (Pants)

Updated: Jul 8

Today we shall draft the Trouser block. From this you can make any style of trousers or shorts and it can even be used for Jumpsuits.

Principles of pattern drafting.

We shall be drafting a whole Front piece and Back piece. Trousers are bifurcated garments as you need two sets of each piece (front and back) for each leg. Depending on the part of the body, some measurements will be divided into 2, and some will be divided into 4. It will all become clearer as we draft.

Basic Pants pattern 1

Tools you will need

  1. Straight ruler

  2. Set square

  3. Curve ruler

  4. Pencils / Eraser /Sharpener

  5. Brown paper/ Drafting Paper - 1 sheet (50L x 50W inches) or 2 sheets ( 50L x 20W inches) each

Measurements you will need (Feel free to work in Inches or Cm)

  1. Waist

  2. Hip

  3. Hip depth

  4. Crotch

  5. Crotch depth

  6. Outseam (Waist to Floor)

  7. Inseam

  8. Waist to knee

  9. Knee circumference

  10. Upper thigh circumference

  11. Foot circumference



Old version - Worksheet only



1. Leaving a space of about 2 inches (5cm) from the top of the paper, Square a line straight down on the right hand side of the paper. Mark Point A at the top of this line.

2. Point A - B = Hip depth

3. Point A - C = Crotch depth

4. Point A - D = Waist to knee

5. Point A - E = Outseam (waist to floor)

6. Square across guidelines to the left side from points A, B, C, D and E.

7. Line A - F = 1/4 Hip measurement (with ease included)

8. Line F-G-H = Square a straight line down from point F stopping on the crotch line (Line C-I)

9. Line H - I = Front crotch extension measurement

10. Line J-K-L-M = Measure Line C-I and mark mid-point. From this point square a straight line up to the waist line and down to the base line. Label as illustrated (Crease Line)

11. F - * =Move inwards 3/8inch (1cm)

12. Line * - N = Waist + Dart measurement. Square up 3/8 inch (1cm) from point N. Label as n1

13. Points O-P = Insert front dart at Point J. Split front dart measurement equally on either side of point J. Label as O and P.

14. Line J - Q = 1/2 Hip Depth measurement

15. Connect points O - Q and P - Q to form dart

16. Connect point P - n1 with a curved line to complete waist

17. Connect points * - I and n1 - B with curved lines to complete centre front and side as illustrated.

18. Line R - S = 1/2 Knee measurement at Point L. Split the measurement equally on either side of point L. Label as R and S.

19. Line T - U = Line RS minus 2inches (5cm). Split the measurement equally on either side of point M. Label as T and U.

20. Connect Points I - R and C - S with gently curved lines

21. Connect Points R - T and S - U with straight lines

That completes the front part.

The Back is a modification of the front. Copy the front unto new paper and flip it horizontally so that the centre front is now on the right hand side.