Abstract: A modular level is formed of unequal length first and second components which may be joined to form a single, elongate level or alternatively joined to form a framing square. Each component includes a series of level vials, enabling each component or joined components to be used for determining horizontal and/or vertical lines. The first component has a pair of pins extending from one end, parallel to its elongate axis. The second component has a first pair of passages in a first end parallel to its elongate axis, for joining the two components end to end to form a single long level. The second component also has a second pair of passages in its second end orthogonal to the first passages, for joining the two components at right angles to form a framing square. A storage compartment may also be provided in one component.