Just buy a bioelectrical impedance scale. They're pretty affordable ($50, I think, or less).
They aren't accurate, but they're precise (there's a difference).
If you step on it once, it will not give you your precise bodyfat (it can vary wildly). But who cares what actual percent BF you are.
What matters is the accuracy on repeated measurements to track changes. That's where the scale is useful. If you step on it at the same time every day, day after day, you will see where the changes are coming from (fat vs muscle).
I have one. I step on it every morning after I piss when I wake up. Write down what it says. Track the changes. It's easy. And the numbers don't fluctuate wildly.
Now, when I prep for a show, a week or two out, the stupid scale will say I'm at 1% BF, which is stupid. I'm probably at 6% or 7%, realistically. But when I first diet, I step on and it'll say 22% or 23% or something like that. Then, I just keep tweaking my diet bit by bit until I see the numbers start to move. Then I know I ride out that caloric intake until I stagnate, then I have to cut a few more calories. Or bump up the cardio. Whatever I feel I can handle at the time.
Or just up the T3. That always works too.