# U-shaped half-turn staircase with N winder treads (180°)

Calculation of the stairs to the second floor with a 180° turn with an arbitrary number of winder treads with the help of online calculator number of materials, drawings, 3D model.

Also see
the Calculator will be available after changes in the relevant parameters.
Click "Calculate" to open the options window.
Choose Drawing:
Distance: 0
Calculation resultsStaircase dimensions
• Angle (Pitch): 33.19 °
• Formula of comfortable stairs (R + G): 44.64 mm
• Blondel's Formula (2R + G): 62.28 mm
• Rise, Step Height: 17.65 mm
• Going: 26.99 mm
• Number of Steps: 16 pcs.
• Staircase Width: 100 mm
• Dimension for correction Total Run #1 (bottom stairway) to make equal Goings: 0 mm
• Dimension for correction intermediate flight of stairs (middle stairway) to make equal Goings: 0 mm
• Dimension for correction Total Run #2 (upper stairway) to make equal Goings: 0 mm
• length: 100 mm
• width: 32.49 mm
• thickness: 4 mm
• volume: 0.013 m3
• length: 100 mm
• width: 32.5 mm
• thickness: 4 mm
• volume: 0.013 m3
• length: 100 mm
• width: 40.47 mm
• thickness: 4 mm
• volume: 0.016 m3
• length: 109.58 mm
• width: 52.11 mm
• thickness: 4 mm
• volume: 0.023 m3
• length: 145.77 mm
• width: 57.73 mm
• thickness: 4 mm
• volume: 0.034 m3
• length: 151.42 mm
• width: 47.25 mm
• thickness: 4 mm
• volume: 0.029 m3
• length: 121.41 mm
• width: 46.49 mm
• thickness: 4 mm
• volume: 0.023 m3
• length: 105.37 mm
• width: 40.16 mm
• thickness: 4 mm
• volume: 0.017 m3
• length: 100 mm
• width: 40.64 mm
• thickness: 4 mm
• volume: 0.016 m3
• length: 110.11 mm
• width: 51.69 mm
• thickness: 4 mm
• volume: 0.023 m3
• length: 146.06 mm
• width: 57.06 mm
• thickness: 4 mm
• volume: 0.033 m3
• length: 151.42 mm
• width: 49.55 mm
• thickness: 4 mm
• volume: 0.03 m3
• length: 119.78 mm
• width: 48.72 mm
• thickness: 4 mm
• volume: 0.023 m3
• length: 104.11 mm
• width: 39.53 mm
• thickness: 4 mm
• volume: 0.016 m3
• length: 100 mm
• width: 33.66 mm
• thickness: 4 mm
• volume: 0.013 m3
• length: 100 mm
• width: 33.65 mm
• thickness: 4 mm
• volume: 0.013 m3
Stair Riser #1
• length: 100 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Stair Riser #2
• length: 100 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Stair Riser #3
• length: 100 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Stair Riser #4
• length: 101.55 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Stair Riser #5
• length: 115.07 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.003 m3
Stair Riser #6
• length: 141.42 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.003 m3
Stair Riser #7
• length: 115.37 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.003 m3
Stair Riser #8
• length: 101.71 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Stair Riser #9
• length: 100 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Stair Riser #10
• length: 101.71 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Stair Riser #11
• length: 115.38 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.003 m3
Stair Riser #12
• length: 141.42 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.003 m3
Stair Riser #13
• length: 113.78 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.003 m3
Stair Riser #14
• length: 100.97 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Stair Riser #15
• length: 100 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Stair Riser #16
• length: 100 mm
• width: 13.65 mm
• thickness: 1.8 mm
• volume: 0.002 m3
Initial parametersDisplay
• Units: cm mm
• Color drawing: paint mm
Type of Stair
• Left Turn:  selected
Stair opening dimensions (horizontal)
• Total Run #1 (Length along bottom stairway): 200 mm
• Total Run #2 (Length along upper stairway): 200 mm
• Distance between the bottom and upper stairways: 80 mm
The mode of stairs calculating, depending on the method of calculating the Going
• Fixed Total Run #1, fixed Total Run #2 and intermediate Total Run (Goings can be different):  selected
Staircase dimensions
• Total Rise (Height from Finished floor level to Finished floor level, FFL-FFL): 300 mm
• Staircase Width: 100 mm
• Dimension MW - minimum Going in the turning part of the staircase (see pics in Help): 10 mm
• Dimension MF - minimum Going, winder treads without nosing (see pics in Help): 4 mm
• Preferable step height (Rise): 18 mm
• Nosing (Tread Overlap): 4 mm
Stair Risers
• Riser Thickness: 1.8 mm
Stair stringers
• Thickness: 6 mm
• Minimum stringer Throat Depth (width): 15 mm
• Number of stringers per 1 stairway: 3 mm
Upper Floor Slab
• Slab thickness: 20 mm
Walls
• Wall thickness: 20 mm
Choose saving method
Bookmark a Website
Keep a reference to the result of the calculation in the section "My bookmarks" in your account.
Share in social network
Help
• Step 1. The choice of the number of rotary stages – 4 PCs, 6 PCs, 8 PCs, N PCs (default N PCs).
• Step 2. The selection of the suitable units of measurement – mm, cm, m, inches, feet.
• Step 3. Specify the means of drawing drawings – monochrome, color.
• Step 4. The definition of call on the stairs – prevoshodnaja (to turn left), left (to turn right).
• Step 5. Determining the horizontal dimensions of the opening along the upper and lower marsh, and the distance between the lower and upper stairs.
• Step 6. The mode of constructing staircases, depending on the method of calculation of the width of the tread – upper, intermediate and lower marsh are exactly the size of the opening / bottom sizes, intermediate, and top automatically / staging according to the dimensions, lower and upper automatically / top according to the dimensions, lower and intermediate automatically.
• Step 7. The input parameters of the stair – width of the March, the height of the opening (if the top step at the level of the 2nd floor, the height of the opening = height of the stairs).
• Step 8. The settings of steps – minimum width rotary stages(and) are in the angle of rotation "parameter MW" and relying on stringer in any other place "parameter MF", the required height of the steps (will be matched as close as possible value), the thickness of the step, the ledge the edge of the step, the top step is below the level of the 2nd floor or level (optional).
MW – the minimum possible distance between the extreme points of the projections of angular steps (or stages) in a straight line, MFminimum length of track on ground any other step(s). The drawing (top view) marked a red – corner steps, green – all the other degrees, and also the parameters MW and MF specifically for this design of stairs. More details about the parameter MW , read the article "Calculation of winder treads", and the optimal values of MF can be found in the block "Recommendations".
• Step 9. Risers – the necessity of application in the design of risers (optional), the thickness of the risers.
• Step 10. The parameters of the stringers thickness and the minimum width of the stringer, and the number one marsh (defaults to 3 PCs).
• Step 11. Ceiling and wall – blocks are only used for 3D visualization and do not affect the final results.
• Step 12. Confirm the entered values and start the calculation of stairs with sweeps 180° with an arbitrary number of winder treads with the button "Calculate".

### Recommendations

To create the most comfortable to operate design, it is recommended to choose the parameters of the stages on the basis of a universal formula "easy stairs" French engineer françois Blondel. This expression is derived in a scientific way and from this it follows that if the step width is reduced, it is necessary to increase the height, and Vice versa – by increasing the width of the steps you need to reduce the height, while keeping the step length in the range 600-650 mm. Also if you are interested in the optimal parameters of the remaining items, please visit the section "Calculation of the stairs online".

Blondel's formula: 2 × h + s = 60/65 cm

• h – the height of the steps;
• 60/65 cm average stride length of a person.

In addition, the parameter MF, which determines the shape of the rotary unit of the ladder and the ground contact surface of the tread in particular. Decreasing the parameter, the ladder will get a more curved and compact (strive to the form of a spiral), but at the same time will decrease bearing capacity of the stage, as reduced area of contact with the stringer. Therefore, if you specify MF less than 10 cm, you should stick to the measures to strengthen the design: the number of stringers for one March should be 3 or more, and the Board steps shall be made of hard wood.

Specify dimensions
Display
DU
CL
Type of Stair
LF
RG
Stair opening dimensions (horizontal)
LB
LT
MD
The mode of stairs calculating, depending on the method of calculating the Going
EX
EB
EM
ET
Staircase dimensions
SH
SW
MW
MF
DH
SC
SF
SP
Stair Risers
HV
HT
Stair stringers
T
WI
QT
4
Upper Floor Slab
ST
Walls
WT