A handheld layout and marking tool including a rule-like member and a sliding handgrip for sliding to a user desire position. The sliding handgrip preferably includes an integrally formed braking device rendering a one hand operable combined sliding handgrip and braking device. A handheld layout and marking tool having a headpiece and a detachable rule-like member for insertion into the headpiece lengthwise to interchangeably form either a framing square or a T-square.