In daily life, people usually like to hang decorations such as photo frames on the wall to decorate the indoor space, but the hanging angle is always inclined and needs to be adjusted to the level repeatedly. The design of this balanced tape measure cleverly solves this problem. Using the plumb line theorem, the tape measure is redesigned. People only need to observe whether the pointer on the tape measure points to the red line to determine whether the hanging photo frame remains level. The whole operation process is simple and intuitive, which can save a lot of time and enhance the user experience. In terms of details, the right side of the tape measure passes through the clever transition between arc and plane to ensure that it conforms to the man-machine and usage habits when holding while being close to the wall. The sliding button on the side of the tape measure is used to lock the tape measure and prevent the tape measure from retracting inward. A certain length of gap is reserved in the middle of the ruler for horizontal marking. In terms of modeling, the tape measure extracts the shape of the leaves and gives them different colors, so that the product is integrated into the use environment, giving users a light and beautiful feeling.