The Ultimate Pants Fit Guide
First, let me start off by saying that one size fits all is an illusion when it comes to pants. As much as we would love to be able to draft patterns that will fit every person perfectly with zero adjustments, unfortunately sometimes it just isn’t possible. Though the measurements of two people can be the same, the shape of their bodies can be wildly different so personal fit adjustments are necessary to ensure a great fit.
As with every pattern, it is always a good idea to make a muslin first so any issues can be addressed before using your good fabric. Be sure to use a fabric with a similar weight and stretch for the best results. When possible, use basting stitches to make it easier to remove seams and make adjustments.
The crotch area is the most common place fit issues will arise in pants. Most often, the shape of the crotch curve differs from the shape of the body which will require personal fit adjustments to ensure a custom fit. In some cases, other adjustments may be necessary in tandem with the crotch adjustment.
Draglines radiating down and away from the front crotch.
If there are draglines radiating down and away from the crotch that give the appearance of a frown, it is likely the front crotch needs to be shortened. Remove width at the inseam. This should be done in small increments until the desired fit is achieved. Ensure the new crotch/inseam blends smoothly down the thigh.
Draglines radiating down and away from the front crotch.
If there are draglines radiating up and away from the crotch that give the appearance of a smile, it is likely the front crotch needs to be lengthened. Add width to the inseam. This should be done in small increments until the desired fit is achieved. Ensure the new crotch/inseam blends smoothly down the thigh.
Vertical draglines along the front crotch.
If there are vertical draglines along the front crotch, there is likely the crotch curve is too flat for the shape of the pubic area and a round pubis adjustment is needed. Scoop the crotch curve in small increments, typically no more than 1/8 (3mm) at a time, until the desired fit is achieved. Keep in mind, if too much fabric is scooped, it may end up affecting the fit through the hip. If this is the case, simply add some width to the outer hip and blend into the current outseam. It is helpful to try on the pants inside out so you can easily see the seam. Pinch out the excess to fit the curve of the body. Baste the adjustment and try on again. Once the fit is perfected, transfer the adjustments to the pattern pieces.
Horizontal draglines on the front crotch.
If there are horizontal draglines on the front crotch, the crotch curve may be too deep for the shape of the pubic area or a bit more ease is needed through the hip. Unfortunately, for this adjustment, a second muslin will probably be required.
If you see these draglines extending to the outer hip and the pants seem too tight, the crotch curve may be fine, and you could just need a bit more ease through the hip to lessen the tension. In this case let out the side seams starting level with the crotch, letting out a couple inches above and below. Try them back on and if the draglines are gone, simply add a bit of width to the outer hip of the pattern piece and blend into the outseam.
If the ease feels comfortable, straighten the front crotch curve. Start out with a straighter curve and sew with a basting stitch. Try on the pants inside out so you can easily see the seam. If needed, pinch out any excess to fit the curve to the body. Baste the adjustment and try on again. Once the fit is perfected, transfer the adjustments to the pattern pieces.
Wedgie
If the back crotch is uncomfortable and digging into the buttocks, it is likely the curve isn’t deep enough and needs to be scooped and reshaped to fit the shape of the body. In some cases, it may need to be extended as well. Try on the pants on inside out and pinch out the excess fabric along the back crotch curve until the wedgie subsides. In certain cases, scooping the curve too much can change the fit through the hip and thighs so be mindful. Baste the adjustment and try on again. If the fit is good, make a permanent stitch. Apply the adjustment to the pattern piece.
Back Inner Thigh Vertical Draglines
If there are vertical draglines on the inner thigh, a thin thigh adjustment is likely needed. Take in the back inseam at the crotch and draw a new inseam, blending smoothly into the thigh. Depending on how much excess needs to be removed, it may be necessary to take away from the front inseam as well.
If you are looking for a quick fix without any crotch adjustments, contour the thigh shape only and blend into the existing crotch. Make this adjustment 1/8” (3mm) at a time to ensure the leg does not become too tight. It is best to try the pants on inside out and pinch out the excess fabric along both the inner thigh to fit the shape of the leg. Baste the adjustment and try on again. Repeat until the desired fit is achieved. If this quick adjustment fixes the issue, apply the adjustment to the pattern pieces.
Diagonal Draglines Below the Buttocks Pointing Towards the Crotch
If there are diagonal draglines below the buttocks that point toward the crotch, a full thigh adjustment is likely needed. Extend the back inseam at the crotch and draw a new inseam, blending smoothly into the thigh.
Draglines all over the buttocks all pointing to the center back seam.
If there are draglines all over the buttocks that all point to the center back seam, it is likely a full seat adjustment is needed. Draw a line from the center back of the pattern piece to the outer hip. Cut from the center back to the hip, leaving approximately 1/8” (3mm) uncut. Rotate the top piece up to add a bit of length and width through the seat. Draw a new center back curve, blending smoothly into the existing curve. Do the same on the outseam.
Pooling Above the Buttocks or Plumber’s crack.
If there is pooling above the buttocks, pinch out the fabric until it becomes smooth to see how much to remove. Lower the rise at the center back only, draw a new line, blending into the waist/hip. This method can also be used to adjust the front rise as well.
Low Rise/Plumber’s Crack
If the pants feel like they are falling down or sitting too low in the back, determine how much additional length is needed in the rise. Extend the rise at the center back only, blending into the waist/hip. This method can also be used to adjust the front rise as well.