Second-floor window over a patio
Viewpoint 4.6 m (15 ft 1 in) high; patio from 9 to 13 m away; seated heads at 1.2 m.
Screen 7.5 m from the window: 2.64 m (8 ft 8 in). Moved to 8.7 m, right beside the patio: 2.33 m (7 ft 8 in).
Open in plannerPrivacy Sightline Planner
How tall does your privacy screen need to be?
See exactly where a privacy screen needs to go — and how tall it needs to be.
Start planning
Free · no account · calculations run locally in your browser
- Minimum height and width from real sightline geometry
- Drag the screen and watch the requirement change
- Several windows and balconies at once
- Save, share, print or export your plan
Simple: measurements
Height of the viewer’s eyes above your ground level. A person standing at ground level ≈ 1.6 m (5 ft 3 in); at a typical second-floor window ≈ 4.5 m (15 ft).
Horizontal distance from the viewer to the nearest edge of the area you want hidden.
Horizontal distance from the viewer to where the screen would stand. It must be less than the distance to the private area.
How high above the area’s floor must be out of view. Seated adults ≈ 1.2 m (4 ft), standing adults ≈ 1.8 m (6 ft), the ground itself = 0.
Leave empty to see only the required height. Drag the top of the screen in the side view to change it.
Side view
Profile from the observer to the private area. Drag the screen sideways to move it, or drag its top handle to change its height.
Tip: every handle can be focused with Tab and moved with arrow keys (Shift = larger steps).
Top view
Plan view showing how wide the screen must be to catch the outermost sightlines.
- Hidden
- Visible
- Privacy screen
- Limiting sightline
- Blocked beyond the screen
Minimum screen height
2.64 m / 8 ft 8 in
Recommended with margin: 2.84 m / 9 ft 4 in
Still visiblePart of the private area can still be seen.
- Current screen height
- 2.40 m
- Minimum required
- 2.64 m
- Recommended with margin
- 2.84 m
- Difference
- −0.44 m
- Width needed
- 3.95 m
- Current width
- 3.96 m (auto-sized)
- Coverage
- 65%
- Protected area
- 11.7 m²
- Visible area
- 6.34 m²
- Distance from private area
- 1.50 m
- Distance from limiting observer
- 7.50 m
- Limiting observer
- Second-floor window
Required values are rounded up to the displayed precision. Result accuracy depends on your measurements.
Geometric height required. This is not a statement of what local rules allow. Check local rules before building.
Why this result
At this position, the highest sightline runs from Second-floor window to the far edge of the private area. It crosses the screen line 2.64 m above the screen’s base.
Adding your 0.20 m safety margin produces a recommended height of 2.84 m.
The screen run has been sized automatically to the 3.95 m needed to catch the outermost sightlines.
The screen is 0.44 m lower than recommended, and about 35% of the private area remains visible.
Moving the screen 1.00 m closer to the private area would lower the required height to 2.58 m, but it would need to run 4.32 m. A screen closer to the area intercepts the downward sightline lower, and catches a wider spread of sightlines.
Calculations run locally in your browser. Your measurements are not sent anywhere.
Compare screen positions
Moving a screen can change the required height dramatically. Compare up to three positions using your current observers, private area and margin.
| Option | Screen distance | Height needed | Width needed | Approx. screen area | Coverage with your current screen | Actions |
|---|---|---|---|---|---|---|
| Option ANear the observer | 4.22 m | 2.03 m | 8.53 m² | 0% | ||
| Option BHalfway | 3.63 m | 2.85 m | 10.3 m² | 0% | ||
| Option CNear the private area | 2.80 m | 4.01 m | 11.2 m² | 71% |
Across these options the height needed ranges from 2.80 m to 4.22 m.
Find best position
Tell the planner where a screen could go and your limits. It tests hundreds of positions and shows options that satisfy them.
Distances from the reference line (the observer side).
Saved plans
No saved plans yet. Plans are stored only in this browser.
Privacy Sightline Planner
Privacy screen plan: Patio vs. second-floor window
Results
| Minimum screen height | 2.64 m (8 ft 8 in) |
|---|---|
| Recommended with margin | 2.84 m (9 ft 4 in) |
| Width needed | 3.95 m (13 ft 0 in) |
| Current screen height | 2.40 m |
| Current width | 3.96 m (auto-sized) |
| Coverage | 65% |
| Protected area | 11.7 m² |
| Visible area | 6.34 m² |
| Distance from private area | 1.50 m |
| Limiting observer | Second-floor window |
| Result | ✕ Still visible |
At this position, the highest sightline runs from Second-floor window to the far edge of the private area. It crosses the screen line 2.64 m above the screen’s base.
Adding your 0.20 m safety margin produces a recommended height of 2.84 m.
The screen run has been sized automatically to the 3.95 m needed to catch the outermost sightlines.
The screen is 0.44 m lower than recommended, and about 35% of the private area remains visible.
Moving the screen 1.00 m closer to the private area would lower the required height to 2.58 m, but it would need to run 4.32 m. A screen closer to the area intercepts the downward sightline lower, and catches a wider spread of sightlines.
Diagrams
Side view
Top view
Measurements
| Observers: Second-floor window | Window · Distance from reference line: 0.00 m · Left/right offset: 0.00 m · Floor level above ground: 3.00 m · Eye level above that floor: 1.60 m · Window bottom edge (sill) above floor: 0.90 m · Window top edge above floor: 2.10 m · Window / balcony width: 1.20 m · Viewpoint height used: 4.60 m |
|---|---|
| Private area | Patio seating (seated adults) · Distance from reference line to near edge: 9.00 m · Area depth: 4.00 m · Area width: 4.50 m · Left/right offset of center: 0.00 m · Area floor elevation: 0.00 m · Height to hide: 1.20 m |
| Screen / barrier | Privacy screen · Distance from reference line: 7.50 m · Screen height: 2.40 m · Size the width automatically to what is needed · Left/right offset of center: 0.00 m · Rotation: 0° · Ground elevation at the screen: 0.00 m |
| Privacy safety margin | 0.20 m |
Geometric estimate based on the measurements entered. It does not replace checking on site, professional measurement, engineering or architectural advice, or local rules and permits. Check local rules before building.
Created with Privacy Sightline Planner.
How the planner works
Instead of guessing, the planner draws the straight lines of sight between where someone could look from and the space you want to keep private, then measures where your screen must interrupt them.
Add the observer
A neighbor’s window, a balcony, or a person on a patio. Enter how high their eyes are and how far away they are.
Define the private area
Your patio, pool, hot tub or deck: where it starts, how large it is, and how high people there need to be hidden.
Place the screen
Type a distance or drag it in the side and top views. Every change recalculates immediately.
Read the dimensions
Minimum height, recommended height with margin, width needed, coverage and which sightline is limiting.
Worked examples
Typical situations calculated with the same engine the planner uses. Open any of them to adjust the numbers to your own property.
Neighbor’s patio across a fence
Standing neighbor with eyes at 1.7 m (5 ft 7 in); sun loungers 6–10 m away, reclining height 0.9 m.
Boundary 4 m from the neighbor: 1.38 m (4 ft 7 in) — a common 1.8 m (6 ft) fence covers it.
Open in plannerThird-floor balcony over a hot tub
Balcony floor 6 m up plus 1.6 m eye height; hot tub 14–16.5 m away; bathers’ heads at 1.1 m.
Screen 0.5 m from the tub: 2.29 m (7 ft 6 in). Halfway, at 7 m: 4.85 m (15 ft 11 in) — overhead cover is the realistic answer.
Open in plannerThe geometry behind the result
A line of sight is a straight line. If the viewer’s eyes are at height ho and the top of what you want hidden is at ht, a screen standing at a fraction s of the horizontal distance between them meets that line at:
crossing height = h_o + (h_t − h_o) × s
required screen height = highest crossing + safety margin
The planner does not rely on a single line. It evaluates every active observer (both ends of a window or balcony) against every corner of the private area, because the highest crossing always occurs at one of those corners. The same pairs, projected onto the plan, give the width the screen needs. The hidden and visible parts of the area are then computed exactly by intersecting the “shadow” each viewpoint casts behind the screen.
This makes the result a geometric estimate based on your measurements: if a measurement is approximate, so is the answer. Adding a safety margin covers taller viewers and small measuring errors.
Guides and calculators
Focused explanations for specific situations, each with worked numbers.
-
Privacy Screen Height Calculator
Calculate the minimum screen height from the viewer’s eye height, distances and what you want hidden.
-
Privacy Screen Distance Calculator
Already have a screen of a certain height? Find every position where it still blocks the view.
-
Privacy Fence Sightline Calculator
See how much of your yard a boundary fence actually hides — its “privacy shadow”.
-
How to Block a Second-Story Neighbor’s View
Why tall fences rarely stop views from upstairs windows, and which placements do.
-
Privacy From Upstairs Neighbors
Balconies and windows directly above: when vertical screens stop working and overhead cover takes over.
-
Privacy Screen Placement: Where Should It Go?
The height-versus-width trade-off of moving a screen between the viewer and your seating area.
-
How High Should a Privacy Screen Be?
Worked examples for common situations, from a neighbor’s patio to a third-floor window.
-
Backyard Privacy Planner
Plan a whole yard with several neighboring windows, balconies and seating zones.
-
Privacy Fence vs. Privacy Screen
A geometric comparison: fixed boundary line versus a screen placed where it works best.
-
How Sightlines Affect Privacy
The geometry behind privacy: similar triangles, privacy shadows, view cones and elevation.
Frequently asked questions
How tall should my privacy screen be?
It depends on four measurements: how high the viewer’s eyes are, how far away they are, where the screen stands and how high the thing you want hidden is. The required height is where the highest sightline crosses the screen’s position. A neighbor at ground level across a fence often needs less than 1.8 m (6 ft); a second-floor window can need well over 2.5 m (8 ft) unless the screen stands close to your seating. Enter your numbers in the planner above to get your own figure, then check local rules before building.
Does screen position affect the required height?
Yes, often dramatically. When the viewer looks down on your space, a screen placed close to the area you want hidden intercepts the sightline where it has already dropped, so it can be lower. The trade-off is width: near the area, the sightlines to its left and right edges are further apart, so the screen must be wider. Use Compare screen positions in the planner, or read privacy screen placement.
How can I block the view from a second-floor window?
Measure the window’s height above your ground (roughly the floor level plus about 1.6 m / 5 ft 3 in eye height), its horizontal distance and your seating area. Then move the screen in the planner: the closer it gets to your seating, the lower it can be. For very steep views, overhead cover near the seating is usually more practical. See how to block a second-story neighbor’s view.
Should a privacy screen be closer to my patio or the neighbor?
When the neighbor looks down at your patio, closer to your patio usually needs less height but more width. When the neighbor is lower than the area being hidden (for example a raised deck seen from a lower yard), the opposite is true: a screen closer to the viewer needs less height. The planner’s Find best position tool shows both the lowest and the shortest option for your case.
How is the minimum privacy-screen height calculated?
With similar triangles. For a viewpoint at height ho and a target point at height ht, the straight sightline crosses a screen that stands at a fraction s of the horizontal distance at height ho + (ht − ho) × s. The planner evaluates every observer against the corners of the private area, takes the highest crossing and adds your safety margin. Width comes from where the outermost sightlines cross the screen line in plan view. Details: how sightlines affect privacy.
Can I use feet and inches?
Yes. Choose feet + inches, feet, inches, meters, centimeters or millimeters from the Units menu. All values are stored in meters internally, so switching units never changes your plan; results are rounded up to the nearest displayed step (1 cm or 1 in).
Can I plan for multiple neighboring windows?
Yes. In Advanced mode, add up to eight observers — windows, balconies or people — each with its own position, floor level and width, and turn them on or off. The screen must block all active observers, and the planner tells you which one is the limiting sightline.
Are local fence-height laws included?
No. The planner calculates what is geometrically needed to block a view. It does not know, and does not state, what height is allowed where you live. Rules on fence and screen heights, setbacks and permits vary by country, municipality and neighborhood association, so check with your local authority before building.
Does the calculator store my measurements?
Only in your own browser. Calculations run locally and nothing is sent to a server. Your working plan and any plans you save are kept in your browser’s local storage so they are still there next time; you can delete saved plans at any time. A share link contains the measurements of that plan, so only share it with people you choose. See the privacy policy.
Results are geometric estimates based on the measurements you enter. They do not replace checking on site, professional measurement, engineering or architectural advice, or local rules and permits. Read the disclaimer.