Stem Count Calculator
How many stems a vase arrangement needs, from the opening diameter, the density you want and the bunch size.
At a glance
- What you enter
- Type of arrangement, Vase opening diameter, Stems per centimetre of opening for the basic spacing, Diameter of one flower head, How full you want it, How many arrangements, Stems in one wholesale bunch, Focal flowers as a share of the stems, Price per stem
- What you get
- Stems per arrangement, Stems for all the arrangements, Focal flowers, Secondary flowers, Filler and foliage, Bunches to order, Stems you will own, Spare stems, Cost of the flowers, Flower cost per arrangement, Stems per litre of opening area
- Formula shown
- Yes, every step, right below your results.
- Cost and privacy
- Free, no account needed, and nothing you type is stored.
See worked examples ↓ Read the FAQ ↓ Share this calculator ↓
Results are estimates for general information only, always verify with a professional or official source before acting on them.
How to use the Stem Count Calculator
- 1 Enter Type of arrangement
- 2 Enter Vase opening diameter (cm), Measured across the inside of the rim. A narrow necked vase holds fewer stems than a wide one of the same height.
- 3 Enter Stems per centimetre of opening for the basic spacing (stems per cm), One stem per 2.5 cm is 0.4 stems per centimetre, which is the spacing rule for large blooms such as hydrangeas and lilies.
- 4 Enter Diameter of one flower head (cm), A hydrangea is 15 to 20 cm, a rose 8 to 10, a spray rose head 5 to 7, a carnation 5 to 6.
- 5 Enter How full you want it (times), One is a standard full arrangement, 0.8 is light and airy, 1.3 is dense and domed.
- 6 Enter How many arrangements
- 7 Enter Stems in one wholesale bunch, Wholesale flowers commonly come in bunches of 10 or 25.
- 8 Enter Focal flowers as a share of the stems (%), Larger, more expensive blooms. Twenty percent is a working figure, more for a formal arrangement.
- 9 Enter Price per stem, Your own figure. Flower prices move with the season, the variety and the market.
- 10 Press Calculate. You get Stems per arrangement, Stems for all the arrangements, Focal flowers, Secondary flowers, Filler and foliage, Bunches to order, Stems you will own, Spare stems, Cost of the flowers, Flower cost per arrangement, Stems per litre of opening area, and every intermediate step stays visible under "How is this calculated?"
- 11 Change one number at a time to see what moves the result, that is usually the most useful thing a calculator can tell you.
Worked examples
Real numbers run through this calculator. Open any example to load it into the form above and change it.
One vase with a 12 cm opening
Spray roses at a 6 cm head size, a full arrangement at 0.4 stems per centimetre.
You enter
- Type of arrangement
- 1
- Vase opening diameter
- 12 cm
- Stems per centimetre of opening for the basic spacing
- 0.40 stems per cm
- Diameter of one flower head
- 6 cm
- How full you want it
- 1 times
- How many arrangements
- 1
- Stems in one wholesale bunch
- 10
- Focal flowers as a share of the stems
- 20%
- Price per stem
- $1.20
You get
- Stems per arrangement
- 48
- Stems for all the arrangements
- 48
- Focal flowers
- 10
- Secondary flowers
- 20
- Filler and foliage
- 20
- Bunches to order
- 5
- Stems you will own
- 50
- Spare stems
- 2
- Cost of the flowers
- $60.00
- Flower cost per arrangement
- $60.00
- Stems per litre of opening area
- 42.44
The spacing rule gives 4.8 as the skeleton and the head based count gives 48, so 48 stems: 10 focal, 20 secondary and 20 of filler, which is five bunches of ten.
A vase of hydrangeas
A 15 cm opening and a 17 cm head size.
You enter
- Type of arrangement
- 1
- Vase opening diameter
- 15 cm
- Stems per centimetre of opening for the basic spacing
- 0.40 stems per cm
- Diameter of one flower head
- 17 cm
- How full you want it
- 1 times
- How many arrangements
- 1
- Stems in one wholesale bunch
- 5
- Focal flowers as a share of the stems
- 30%
- Price per stem
- $4.50
You get
- Stems per arrangement
- 6
- Stems for all the arrangements
- 6
- Focal flowers
- 2
- Secondary flowers
- 3
- Filler and foliage
- 3
- Bunches to order
- 2
- Stems you will own
- 10
- Spare stems
- 4
- Cost of the flowers
- $45.00
- Flower cost per arrangement
- $45.00
- Stems per litre of opening area
- 3.40
The spacing rule gives 6 stems but the packing limit caps heads this large at 2, so 6 hydrangeas fill the vase on the spacing rule: a very different order from the spray roses for a similar vase.
Ten table arrangements
Ten small vases with a 7 cm opening, carnations at a 5 cm head.
You enter
- Type of arrangement
- 1
- Vase opening diameter
- 7 cm
- Stems per centimetre of opening for the basic spacing
- 0.40 stems per cm
- Diameter of one flower head
- 5 cm
- How full you want it
- 0.90 times
- How many arrangements
- 10
- Stems in one wholesale bunch
- 25
- Focal flowers as a share of the stems
- 15%
- Price per stem
- $0.80
You get
- Stems per arrangement
- 14
- Stems for all the arrangements
- 140
- Focal flowers
- 21
- Secondary flowers
- 60
- Filler and foliage
- 60
- Bunches to order
- 6
- Stems you will own
- 150
- Spare stems
- 10
- Cost of the flowers
- $120.00
- Flower cost per arrangement
- $12.00
- Stems per litre of opening area
- 363.78
The head based count gives about 14 stems each, so 140 stems in total, which is six bunches of 25 and a 10 stem surplus.
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