What is the maximum staircase pitch in the UK?

42 degrees for a private staircase serving one dwelling under Approved Document K. Utility and general access stairs have no explicit pitch limit but tighter rise and going limits produce shallower flights.

Do all steps have to be the same height?

Yes. Every riser in a flight must be equal and every going must be equal under Part K. An odd step breaks walking rhythm and is a leading cause of stair falls. Floor finish thicknesses are accounted for so finished rises stay uniform.

Staircase Rise & Going Calculator — Instant Part K Compliance Check

Q: How do I calculate the rise and going of a staircase?

Divide the floor-to-floor height by a target rise of around 200mm to get the riser count, then divide the height by that count for the exact rise. A straight flight has one fewer tread than risers, so divide the available run by (risers minus 1) for the going. For a private UK staircase: rise maximum 220mm, going minimum 220mm, pitch maximum 42 degrees, and 2R+G between 550-700mm.

Q: How many steps do I need for a 2.7m floor height?

For 2,700mm floor-to-floor, 13 risers gives a 207.7mm rise and 14 risers gives 192.9mm - both compliant for a private staircase. 12 risers would need 225mm, exceeding the 220mm maximum.

Q: What is the 2R+G rule?

Twice the rise plus the going should fall between 550mm and 700mm. It approximates a natural stride on a slope - steeper stairs need shorter goings. A flight can meet every individual limit and still feel awkward if 2R+G falls outside this range.

Q: What if my staircase doesn't fit the available space?

In order of cost: steepen the flight toward 42 degrees by shortening the going (staying at 220mm or above), change to an L-shape or U-shape with a landing, use winder treads through the turn, or enlarge the floor opening. Space saver stairs are permitted for loft access to a single room.

Enter your floor-to-floor height and the horizontal run available for the staircase, and this calculator works out the riser count, individual rise, going, pitch and the 2R+G comfort value — then checks every figure against UK Building Regulations Approved Document K and gives you an instant PASS or FAIL with the exact reason. Built by Continox, the team behind the UK's most-read Part K staircase regulations guide.

220mm

Max Rise (Private)

220mm

Min Going (Private)

42°

Max Pitch (Private)

550–700

2R+G Comfort Range

Free Design Tool

Rise & Going Calculator

Adjust the sliders — the design and the Part K checks update instantly.

Floor-to-Floor Height (incl. floor finishes)

2,700mm

Available Horizontal Run (straight flight)

2,750mm

Staircase Category (Approved Document K)

Part K Compliance Result

PASS ✓

This straight flight complies with Approved Document K for a private staircase

Risers

208mm

Rise

229mm

Going

42.2°

Pitch

645

2R+G (550–700)

Design This Staircase With Continox →

Indicative straight-flight design tool for England & Wales (Approved Document K). Scotland and Northern Ireland use separate standards. Winders, tapered treads and landings have additional rules — see the full regulations guide. Continox confirms final dimensions with a free site survey and full drawings for Building Control.

Quick Answer — At a Glance

To calculate a staircase: divide the floor-to-floor height by your target rise to get the riser count (e.g. 2,700mm ÷ 200mm ≈ 13–14 risers), then divide the height by that count for the exact rise. A straight flight has one fewer tread than risers, so divide the available run by (risers − 1) for the going. For a private UK staircase, Part K requires: rise 150–220mm, going 220–300mm, pitch ≤42°, and the comfort formula 2R+G between 550 and 700mm. If your run is too short, the fixes are a steeper (but compliant) pitch, an L-shape with winders, or relocating the flight.

The Part K Limits by Staircase Category

Approved Document K sets different dimensional limits depending on who uses the staircase. A staircase inside a single home has the most relaxed rules; a staircase in a public building the strictest. The calculator applies the correct set automatically.

Category	Max Rise	Min Going	Max Pitch	Typical Use
Private	220mm	220mm	42°	Houses, flats — within one dwelling
Utility	190mm	250mm	—	Plant rooms, stores, maintenance access
General access	170mm	250mm	—	Offices, shops, common stairs in flats

All risers in a flight must be identical. Part K requires every step in a flight to have the same rise and the same going — a single odd step is non-compliant and, statistically, the step people trip on. This is why the calculator divides the total height exactly by the riser count rather than letting you pick a "nice" round rise: the maths has to close to the millimetre, and on site the first riser is adjusted for floor finishes so the finished flight stays uniform.

The Three Formulas Behind the Tool

Rise = Floor-to-Floor Height ÷ Number of RisersEvery riser identical — Part K allows 150–220mm for private stairs

Pitch = atan(Rise ÷ Going)Must not exceed 42° for private staircases

2R + G = 550–700mmTwice the rise plus the going — the comfort rule that makes stairs feel natural underfoot

The 2R+G formula reflects how people actually walk: a steeper rise needs a shorter going and vice versa, because a human stride is roughly constant. A flight that passes the individual rise and going limits but lands outside 550–700mm will feel awkward — too cramped or too stretched — even though each number looks fine in isolation. Full worked examples in our 2R+G formula guide.

What to do when the run is too shortThe most common failure is going below the minimum because the stairwell is too short for the floor height. The compliant fixes, in order of cost: steepen the flight toward (but not past) 42° by reducing the going toward 220mm; switch to an L-shape or U-shape with a quarter or half landing, which resets the run; use winder treads through the turn (compliant if the centre-line going meets the minimum); or enlarge the floor opening — check the knock-on effect with our stairwell opening calculator. Loft conversions get limited relaxations — headroom can drop to 1,900mm in places — but rise, going and pitch limits still apply.

Worked Example — Typical UK House

Floor-to-floor 2,700mm, private staircase, 2,750mm of run available. Try 13 risers: rise = 2,700 ÷ 13 = 207.7mm ✓ (under 220). A straight flight of 13 risers has 12 treads, so going = 2,750 ÷ 12 = 229.2mm ✓ (over 220). Pitch = atan(207.7 ÷ 229.2) = 42.2° ✗ — just over the limit. The fix: stretch the run to 2,800mm, giving a going of 233.3mm and a pitch of 41.7° ✓, with 2R+G = 648.7 ✓. Fifty millimetres of extra run is the difference between a refused and an approved staircase — which is exactly why this calculation is worth doing before any joinery is ordered.

Rise & Going — FAQ

Common questions about UK staircase dimensions and Part K.

Divide the total floor-to-floor height by a target rise of around 200mm to get the riser count, then divide the height by that count for the exact rise (all risers must be identical). A straight flight has one fewer tread than risers, so divide the available horizontal run by (risers − 1) for the going. Check: rise ≤220mm, going ≥220mm, pitch ≤42° and 2R+G between 550–700mm for a private UK staircase.

For a 2,700mm floor-to-floor height, 13 risers gives a rise of 207.7mm and 14 risers gives 192.9mm — both compliant for a private staircase. 12 risers would need a 225mm rise, which exceeds the 220mm maximum. Fewer risers means a shorter flight but a steeper climb; the right answer depends on the run available.

42 degrees for a private staircase serving one dwelling. Utility and general access stairs have no explicit pitch limit, but their tighter rise and going limits (190/250 and 170/250) produce shallower flights in practice. Space saver stairs for loft conversions are a special case with alternating paddle treads — see our staircase regulations guide.

Twice the rise plus the going should fall between 550mm and 700mm. It approximates a natural human stride on a slope: steeper stairs need shorter goings, shallower stairs longer ones. A flight can meet every individual limit and still feel wrong underfoot if 2R+G is outside the range — which is why Part K includes it as guidance and why our designs target the 590–650 sweet spot.

Yes — every riser in a flight must be equal, and every going must be equal. People navigate stairs on muscle memory; an odd step breaks the rhythm and is a leading cause of stair falls. On site, floor finish thicknesses (tiles, engineered boards) are accounted for at the top and bottom so the finished rises stay uniform — one reason a professional survey measures finished floor levels, not structural slabs.

In order of cost: steepen the flight toward 42° by shortening the going (staying at or above 220mm); change the layout to an L-shape or U-shape with a landing; use winder treads through the turn; or enlarge the floor opening. For lofts, space saver stairs with alternating treads are permitted for access to a single room. A free Continox survey resolves this in one visit — we model the compliant options in 3D before anything is manufactured.

From Numbers to Staircase

Free Survey + Compliant Design in 3D

Take your figures to a free on-site survey: Continox models your staircase in 3D, confirms Part K compliance, and delivers a fixed-price quotation with full drawings for Building Control — within 24 hours.

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