You are looking for "deflection ratings". It is a chart you can find on line. That is the EASY part. The HARD PART is MEASURING the joist distances. Usually you have to get underneath the floor and view/measure the "joists on centre". That means to place your measuring tape on the CENTRE of floor joist "A" and then measure to the next joist "B" to the MIDDLE/centre of the joist. You will do this for as many joists as you can. Write them down.

Now go upstairs and find the Deflection Rating chart and compare your measurements to the chart's measurements. And to be clear, 1/2" plywood is RARELY good enough to tile over top of. You would have to have joists every foot. This means you will need to ADD more plywood just to reach the rigidity/deflection rating for the TILE you want to use. Which means you have to KNOW which tile (or at least the SIZE you want to use) before you add thickness.

And cement board does NOT add rigidity. It is simply a bonding substrate for tile. It is also used to "add floor height" when needed. It is NEVER used to "stop plywood from bouncing".

As Sophie so clearly points out, this is a "rip out and redo the whole thing" type of reno...if you insist on tile. If you go with sheet products (as your home has been designed to receive) you will be fine with a layer of 1/4" plywood and then new sheet product.

A traditional subfloor assembly usually achieves: 2 layers with a minimum thickness of 3/4". This is VERY common. Right now you are "missing" 1/4". Which is why we know your home was designed for sheet vinyl and carpet. They are the ONLY products that accept 1/2" plywood subfloors. And the 1/2" plywood subfloors can only accept sheet vinyl and carpet. It really is a dead end street.

To add in tile, you need to remove the kitchen. Add the RIGHT amount of thickness of plywood (which is why you need to assess the "joist on centre" measurements) of the ENTIRE SPACE. Shim the cabinets another 1/2" and then reinstall cabs. Tiles are then installed after the cabinets/counters have been put back....remember to tile in the areas under the appliances.

Now you get the joy of discovering that the kitchen floor is MORE THAN AN INCH higher (possibly 2") than it was before you started (tile adds as much as 3/4" after installation). That means your TRANSITIONS to other floors is going to be a MESS. Some of these transitions could be HUGE. It could be 2" or more "step down" to the next floor. Now we have to look at either removing ALL flooring and adding 3/4" plywood throughout OR living with some of the nastiest, toe-stubbing transitions, in the business.

Either way it is going to hurt. Please reconsider a handsome sheet vinyl in the look you want. You can spend as much as $10/sf (that means almost $100/square yard) on a sheet vinyl and STILL be cheaper than tile.