Cutting Vinyl Siding
This is probably the quickest and easiest way to cut siding. This method is best for long trimming cuts that will be hidden by trim such as J - Channel.
Measure and mark the piece to be cut.
Carefully score the siding along your desired cut line with a utility knife.
Once you've scored the entire piece of siding, bend the piece until it cracks at the score line.
Bend the other way and the siding should break into two pieces.
The cut edge will be as straight as your initial score line.
Best for long pieces that need cut such as top pieces or around windows and doors.
Tin snips work great for those odd shaped cuts. Be sure to use yellow handle tin snips. Yellow makes a straight cut. They also come in handy for small short cuts in tight places.
I wouldn't recommend using these for visible end cuts. See my Vinyl Siding Cutting Jig for end cuts.