Parasol Size Calculator
An undersized parasol leaves half the table baking in direct sun, while an oversized one can overwhelm a small patio. Enter your table shape and dimensions below to find the parasol size that will properly shade everyone sitting at it.
Work out the parasol size you need
Enter your table shape and size, plus how much overhang you'd like.
Recommended parasol diameter:
2m
This covers a needed diameter of around 1.80m, rounded up to the nearest standard parasol size.
Recommended products
A few well-reviewed parasols and garden shade options.
£93.99
Pros
- Solid hardwood frame with a 38mm diameter pole
- UV-treated fabric canopy resists fading
- Pulley cord mechanism makes raising and lowering easy
Cons
- Wooden pole needs occasional weatherproofing treatment
- Polyester
- 3m
£74.99
Pros
- Hangs over a dining set without a central pole in the way
- Crank winding mechanism with adjustable inclination angle
- Heavy-duty 180g polyester canopy copes well with sun and light rain
Cons
- Needs a heavy base (sold separately on some listings) to stay stable in wind
£74.99
Pros
- Golden brown Indonesian hardwood frame looks classic on any patio
- Machine-washable 180gsm spun polyester canopy
- Simple push-up opening mechanism
Cons
- Natural wood finish will weather over time without treatment
Frequently asked questions
Why does a rectangular table need a bigger parasol than a round one of similar size?
A rectangular table has a longer diagonal than its length or width alone, and a parasol needs to cover that full diagonal plus overhang, so rectangular and cantilever parasols usually need to be sized larger than you might first expect.
How much overhang should a parasol have past the table edge?
Around 30cm of overhang on each side is a good general guide, giving shade to anyone sitting at the table without the parasol looking oversized for the furniture underneath it.
Should I size up if I want shade in the early morning or late afternoon?
Yes — the sun sits lower in the sky at those times, so a bigger parasol or one with a tilting mechanism will give you noticeably better coverage than a smaller one sized only for midday shade.
Is a bigger parasol harder to keep stable in the wind?
Generally yes — larger canopies catch more wind, so as you size up it becomes more important to pair the parasol with a suitably heavy base or a securely anchored cantilever stand.
How this calculator works
The calculator uses a simple formula to determine the necessary parasol diameter. It begins by asking you to input the length and width of your garden table in centimetres. This measurement is then used to calculate the area of the table surface (length x width).
Next, you specify the percentage of shade you desire – typically between 50% and 80%. The calculator then multiplies the calculated table area by this percentage to determine the shaded area. Finally, it applies a standard ratio of approximately 1.4 metres for every square metre of shaded area to arrive at the recommended parasol diameter. This ratio accounts for the projection needed to effectively block sunlight.
Key Considerations for UK Gardens
- **Sun Angle:** The angle of the sun varies significantly throughout the year in the UK. A parasol sized for summer might leave you shaded in winter when the sun is lower.
- **Garden Orientation:** South-facing gardens receive the most intense sunlight, requiring larger parasols than east or west-facing spaces. Consider your garden’s specific orientation for accurate shade calculations.
- **Table Height:** Taller tables require a greater projection from the parasol to effectively block heat radiating upwards. This calculator assumes a standard table height of 75cm; adjust if you have an unusually high dining set.
- **Wind Conditions:** Larger parasols can be more susceptible to wind damage, especially in exposed UK gardens. Consider purchasing a parasol with robust fixing options and potentially a wind sail for added stability.
Worked example: Shade a 1.5m x 0.8m Table
Let’s say you have a garden table measuring 1.5 metres (length) by 0.8 metres (width). First, we calculate the area: 1.5m x 0.8m = 1.2 square metres. You want to achieve approximately 70% shade – this is entered into the calculator.
The calculator then multiplies 1.2 square metres by 0.7 (70%) giving a shaded area of 0.84 square metres. Applying the standard ratio of 1.4m per square metre gives us a recommended parasol diameter of approximately 1.18 metres, or roughly 118cm. This would correspond to a parasol with an approximate diameter of 120cm available on Amazon UK – a good starting point for your shade requirements.
More questions answered
What does the percentage shade value represent?
The percentage shade value represents the desired amount of sunlight blocked. A higher percentage (e.g., 80%) will provide more shade, but may require a larger and potentially more expensive parasol.
I’ve entered my table dimensions, but the calculator suggests a very large parasol!
Double-check your measurements – even small errors can significantly impact the result. Also, consider that 70% shade is a common target; if you need more extensive protection, increase this percentage in the calculator.
Can I use this calculator for different shaped tables?
The calculator is designed primarily for rectangular tables. For irregularly shaped tables or alfresco furniture sets, it’s best to estimate the area based on the largest surface you want to shade and adjust accordingly.
What if I want to shade a small bistro set?
Reduce the table dimensions in the calculator – inputting a smaller length and width will naturally result in a smaller recommended parasol size. A 1m x 0.6m table would require a smaller parasol.
Does this calculator account for furniture height?
The calculator assumes a standard table height of 75cm, which is the most common height for garden tables and chairs. Adjust your inputs if you have significantly taller or shorter furniture.
What happens if I use a percentage shade value above 100%?
The calculator will still provide a result, but it's important to remember that it’s only a guideline. A 100% shade value would require an extremely large parasol and may not be practical or affordable.
How does the wind affect my parasol size?
Larger parasols are more susceptible to wind damage, especially in exposed UK gardens. Consider purchasing a parasol with robust fixing options and potentially a wind sail for added stability.
Can I use this calculator to find a parasol with a specific pole diameter?
The calculator focuses on diameter based on shaded area, not pole diameter. You'll need to consider the pole diameter separately when selecting your parasol – check product specifications on Amazon UK.
What’s the best time of year to use this calculator?
This calculator is useful year-round, but it’s particularly helpful in spring and summer when sunlight intensity is highest. Remember to consider seasonal sun angles for optimal shade.
If I'm buying a parasol online, what other factors should I consider?
Always check reviews on Amazon UK to gauge the quality of the parasol. Pay attention to the fabric’s UV protection rating and ensure it is suitable for outdoor use. Also, verify the fixing options – robust bases are crucial in windy conditions.