This highly technical calculator translates the 'stretchiness' of a bra band into a scientific measurement of force. You'll input the elastic material's properties and the percentage it's stretched when worn. The calculator then uses physics principles to estimate the tension force in Newtons. This provides an objective measure of how firmly the bra band is hugging your body.

The firmness of a bra band is the most critical factor for support, providing about 90% of a bra's total lift. However, 'firm' is subjective. This calculator provides an objective, scientific way to quantify band tightness. It's invaluable for lingerie designers, custom bra makers, or anyone seeking a truly perfect, technically-sound fit. It helps ensure a band is supportive enough without being dangerously restrictive.

The result is a force value in Newtons, representing the tension in the bra band. A higher number means a tighter, more supportive band, while a lower number indicates a looser, more comfortable fit. There's no single 'correct' number; it's a trade-off between support and comfort. This tool allows you to compare different elastics and stretch percentages on a purely objective basis, leading to a more engineered and personalized fit.

• This calculator is a great tool for DIY bra makers to test and compare different types of elastic.
• A brand new bra should be worn on the loosest hook. As the elastic relaxes over time, you can move to the tighter hooks to maintain the same tension.
• The 'force' of the band should feel evenly distributed around your torso, not concentrated in one spot.
• Different activities may require different levels of band tension. A sports bra, for example, will have a much higher tension force than a sleep bralette.
• Remember that a comfortable level of tension is personal. Use this calculator as a guide, but always listen to your body.