Yes, bathtubs come in many shapes and sizes. And having an option to pick the bathtub for your bathroom yourself is priceless. The experience of having a bath should be enjoyable, so you really need to spend some time picking the perfect tub for your bathroom.
First and foremost: the length and width of the bathtub are obviously affected by how much space there is in your bathroom. Don’t forget to take into account clearance around it to get in and out safely.
Standard size bathtubs are 60 inches (152 centimeters) long and 30 to 32 inches (76 to 81 centimeters) wide.
Now, if your bathroom allows only for standard size bathtub, your height becomes a very important measure. Because anybody over about 6 feet (180cm) tall is likely to find this standard size pretty uncomfortable. The depth of the bathtub comes into play here! Compensate! There are plenty varieties of standard size bathtubs with different depth options. There are also deeper tubs known as soaking tubs (or soak tubs) which are designed in a way that allows you to immerse your body almost completely.
The easiest way to determine if your bathtub is going to be comfortable is simply to go and sit in a few.
For full information on varieties of bathtub sizes check out this infographics:
Image source: http://www.vintagetub.com/clawfoot-tub-sizing-guide