These are some rocket stoves I built last year. They work great and use very little wood, mainly sticks and twigs. The sizes all depend on the size pipe and cans you can find. You can build one with some tin snips a screw driver and a marking pen an awl or punch
Started with a welding rod can and a popcorn can for the first stove, then used an elbow and a short length of stove pipe for the second one. If you cut your can close you can get by without using j-b weld. I just used a couple small sheet metal screws. Small stove pipe is a lot easier.
I attached 4 short legs with 2 screws each. Cut out the hole in the front as tight as possible. Cut a hole in the lid and installed elbow so it extended 1/2 inch above the lid. Fill the inside full to the top with Perlite then slip the lid on and peen a lip over till it touches the lid. Use a couple screws through the lip of the lid to keep it on tight
Time to test. I used a piece of tin to hold up the fire wood and make an air chamber under the wood. I burned a real hot fire the first time to burn out any grease or paint. A Dutch oven fits real nice on top. A burner ring from a camper stove worked fine on top. I built a ring to deflect the wind and direct the heat around the pot.
Time to eat. Made a real nice turkey stew. Found a stove top grill at a thrift store. Great for grilling. You can cook a whole meal with a few sticks of kindling or twigs. Hope this helps you build one of your own.