A leaking bathtub can be a frustrating and costly problem, but there are several steps you can take to fix it. Here’s what you can do:

1. Determine the source of the leak: The first step in fixing a leak is to determine where it is coming from. Check the drain, overflow, and any pipes under the tub for leaks. Look for cracks, chips, or other damage to the surface of the bathtub, and inspect the caulking around the tub for any gaps or cracks.
2. Repair or replace damaged parts: If you find a damaged part, such as a clogged drain or a leaky overflow, you can often repair or replace it yourself or hire a professional to do it.
3. Re-caulk the bathtub: If the leak is coming from a gap or crack in the caulking, remove the old caulking and apply a new bead of caulk around the bathtub.
4. Patch any holes or cracks: If you find any holes or cracks in the bathtub, use a bathtub patch kit or a similar product to fill and repair the damage.
5. Test the repair: Once you have made the repair, fill the bathtub with water and let it sit for several hours to make sure the leak has been fixed.

If you are unable to locate the source of the leak or if the repair is beyond your capabilities, it may be best to call in a professional plumber to assess the situation and make any necessary repairs.