u/Professional_Law28

Is there a formula to know when the number x mark of inches and the number y of centimeters would correspond to each other on a definitely long, and I'd imagine just hypothetical, tape measure? I tried counting on my own, even longer than I'd confess but then got bored and realized I could've just checked a long tape. Internet tells me that they would supposedly never "touch" but doesn't explain me why, is that correct? If so how or why? I'm always fascinated by numbers but I've a hard time understanding them. Thank you all in advance. Edit: thank you all for your answers, just reading them seems simpler that what was in my mind. Thank you all once again.