Kitchen Unit Calculator — Base, Wall & Tall Units

Standard UK kitchen unit widths are 300mm, 400mm, 500mm, and 600mm. Most suppliers including Howdens, Wickes, Magnet and IKEA use these increments. The 600mm unit is the most common as it aligns with standard appliance widths. Corner base units typically require 900-1000mm on each wall side.

It depends on the door’s size and weight rather than a single height cut-off. As a planning guide based on Blum’s published guidance, two concealed hinges suit a door up to roughly 900mm tall within the hinge’s weight limit (Blum heavy-duty hinges carry doors up to about 800mm wide and 25kg on two hinges); three hinges are used for taller or heavier doors (up to about 900mm wide and 40kg), and full-height tall-unit doors typically take four. Heavy solid-wood doors and wide doors over about 600mm may need an extra hinge. Standard concealed hinges (such as Blum 110-degree) are used in almost all modern kitchens. Always check your specific hinge maker’s weight-and-size chart.

Standard UK kitchen plinth height is 150mm (roughly 6 inches). This sits between the bottom of the base units and the floor. Base units are typically 720mm high, plus a 150mm plinth, plus a 40mm worktop, giving a total working height of approximately 910mm which is standard in UK kitchens.

Cornice sits on top of wall units and provides a decorative finish where the units meet the ceiling or soffit. Pelmet fits underneath the wall units and often conceals under-cabinet lighting. Both are measured in linear metres and typically match the door style. Standard cornice is around 40-50mm deep and pelmet is 40-60mm.

Filler panels are essential where units meet walls, appliances, or corners at an angle. They ensure doors and drawers can open fully without catching on walls. A minimum 25mm filler is recommended at wall junctions. Corner units also need fillers to allow adjacent doors to open. Plan for at least 2 filler pieces per kitchen, plus one per corner.