Fence Calculator Philippines
Estimate CHB quantity, fence posts and bays, plastering area and paintable wall area for a preliminary CHB perimeter fence.
Fence Details
Fence Quantity Result
Our free Fence Calculator Philippines helps homeowners, contractors and estimators calculate preliminary quantities for a CHB perimeter fence. Enter the total fence length, CHB wall height, gate or opening dimensions, block allowance and preliminary post spacing to estimate the number of concrete hollow blocks, fence bays and posts, plastering area and paintable wall area.
How to Use the Fence Calculator Philippines
- Enter the total length of the proposed fence alignment.
- Enter the CHB wall height.
- Select the planned CHB thickness.
- Select a CHB allowance or enter a custom percentage.
- Enter any gate or wall openings that need to be deducted.
- Select the preliminary maximum spacing for the fence posts.
- Select whether the CHB wall will be plastered on one face, both faces or not plastered.
- Click Calculate Fence Materials.
The calculator provides a preliminary CHB purchase quantity together with the net CHB wall area, number of regular fence bays and posts, plastering area and approximate paintable wall area.
How to Calculate CHB for a Fence
The first step is calculating the gross wall area.
If the fence contains a gate or another opening, its area is deducted from the gross wall area.
The calculator then estimates the number of CHB from the net wall area.
How Many CHB Are Needed per Square Meter?
For preliminary quantity estimating, the calculator uses a nominal CHB face dimension of approximately 400 mm × 200 mm.
Therefore:
The preliminary block quantity is therefore:
Example CHB Fence Calculation
Consider a simple perimeter fence with:
- Fence length: 30 m
- CHB wall height: 2 m
- No gate deduction
- 5% CHB allowance
The gross and net wall area is:
Estimated base CHB quantity:
A 5% allowance adds:
Total including allowance:
Because blocks are purchased as whole units, the calculator rounds upward to approximately 788 pieces.
How Does the Calculator Deduct a Gate?
A gate reduces the area where CHB will be installed. For example, suppose the same 30 m × 2 m fence contains a gate that is 3 m wide and 2 m high.
Gross wall area:
Gate opening:
Net CHB area:
Base CHB:
With a 5% allowance:
The preliminary purchase quantity therefore becomes approximately 709 CHB.
What CHB Thickness Should I Use for a Fence?
The calculator provides common nominal thickness selections of:
| Nominal CHB Thickness | Approximate Inch Reference | Calculator Effect |
|---|---|---|
| 100 mm | 4 inch | Displayed for project reference; does not change the block face count. |
| 125 mm | 5 inch | Displayed for project reference; does not change the block face count. |
| 150 mm | 6 inch | Default calculator selection; does not change the block face count. |
The appropriate CHB thickness must be determined from the project requirements and structural design. Selecting a thicker block in this calculator does not mean that thickness is structurally suitable for a particular fence.
Why Doesn't CHB Thickness Change the Number of Blocks?
The calculator estimates the number of blocks from the face area of the wall. A nominal 100 mm, 125 mm or 150 mm CHB can have essentially the same nominal face dimensions while differing in wall thickness.
Therefore, changing the thickness does not automatically change the number of CHB needed to cover the same wall face area.
It can, however, affect other construction quantities and structural requirements that are outside this calculator.
How Much CHB Allowance Should I Add?
The calculator provides:
- 0% allowance
- 5% allowance — default
- 10% allowance
- Custom allowance
The allowance can help account for cutting, breakage and other normal quantity differences during construction.
The appropriate allowance is project-specific. The calculator's default 5% should therefore be treated as a preliminary estimating assumption, not a mandatory construction standard.
How Does the Fence Post Calculator Work?
The calculator estimates the number of regular fence bays by dividing the total fence alignment by the selected maximum preliminary post spacing.
For a straight continuous alignment:
Rounding the number of bays upward prevents the resulting average regular bay spacing from exceeding the maximum spacing selected in the calculator.
Fence Post Spacing Example
For a 30 m fence with a selected maximum preliminary spacing of 3 m:
Therefore:
The regular average bay spacing is exactly 3.00 m.
Now consider a 31 m fence:
The calculator rounds upward to 11 bays.
The preliminary regular post count becomes:
Is 3 Meters the Required Fence Post Spacing?
No. The calculator uses 3.00 m as a convenient default preliminary quantity-planning value, but it is not presented as a universal structural requirement for Philippine fences.
Users can select 2.00 m, 2.50 m, 3.00 m or enter a custom spacing.
How to Calculate Fence Plastering Area
The calculator can estimate the wall-face area to be plastered.
For one-face plastering:
For both-face plastering:
For example, a fence with 54 m² of net CHB wall area has:
of plastering when both faces are selected.
The fence calculator intentionally calculates only the plastering area. To estimate cement and sand for the plaster itself, use our dedicated Plastering Calculator Philippines.
How to Estimate the Paintable Fence Area
For preliminary planning, the calculator treats the selected plastered wall faces as the approximate paintable wall area.
For example, if both faces of a 60 m² CHB wall are selected:
The calculator does not estimate liters of primer or paint because coating coverage varies by product, surface condition and number of coats.
Use the Paint Calculator Philippines to estimate paint quantity from the calculated wall area.
Does the Fence Calculator Include Cement and Sand?
No. The Fence Calculator focuses on the overall fence quantity take-off and avoids duplicating the more detailed functions of the site's other calculators.
After obtaining the net CHB wall area, use the CHB Calculator Philippines for a more detailed CHB and mortar estimate.
For plastering materials, use the Plastering Calculator Philippines.
Does the Fence Calculator Include Concrete?
No. The calculator does not automatically calculate concrete for posts, footings or tie beams because doing so would require assumptions about structural dimensions.
Once the approved plans provide the required concrete dimensions, you can use the Concrete Calculator Philippines to estimate the corresponding concrete volume and preliminary materials.
Does the Fence Calculator Calculate Rebar?
No. Reinforcement size, spacing and arrangement should come from the structural design rather than a generic fence quantity calculator.
Once the required bars and spacing are known from the plans, use the Rebar Calculator Philippines for preliminary reinforcement quantity and weight calculations.
What Materials Are Commonly Involved in a CHB Perimeter Fence?
A typical reinforced CHB perimeter-fence project may involve several different work items, depending on the design:
- Concrete hollow blocks
- Cement and sand for masonry mortar
- Reinforced concrete posts or columns
- Footings or foundations
- Reinforcing steel
- Tie beams or wall footings where specified
- Cement plaster
- Primer and paint
- Gates and gate posts
- Excavation and backfilling
This calculator estimates only the quantities that can reasonably be derived without inventing structural dimensions.
Why Doesn't This Calculator Design the Fence Footing?
A fence footing is a structural component. Its required dimensions cannot be determined reliably from fence length alone.
The design may depend on factors such as:
- Soil conditions and allowable bearing capacity
- Fence height
- Wind loading
- Post spacing
- Post and wall dimensions
- Reinforcement arrangement
- Site slope
- Whether the wall also retains soil
- Gate loads and gate configuration
What the Fence Calculator Does Not Design
The calculator does not determine:
- Concrete post or column dimensions
- Footing dimensions
- Footing depth
- Concrete volume for structural components
- Rebar size or spacing
- CHB reinforcement
- Tie-beam dimensions
- Wind-load capacity
- Soil bearing capacity
- Retaining-wall requirements
- Gate-post structural design
- Excavation quantities
These items should be taken from the approved plans and project specifications before final procurement or construction.
Fence Calculator Philippines FAQs
How many CHB do I need for a fence?
Calculate the net wall area after deducting gates and other openings, then multiply by approximately 12.5 CHB/m² for a nominal 400 mm × 200 mm block face. Add the selected project allowance and round upward to whole blocks.
How many CHB are needed per square meter?
The calculator uses 12.5 CHB per square meter based on a nominal 400 mm × 200 mm block face. This is a preliminary estimating factor.
How many CHB do I need for a 30-meter fence?
It depends on the wall height and openings. A 30 m long × 2 m high wall with no openings has 60 m² of CHB area, equivalent to approximately 750 CHB before allowance. With 5% allowance, the calculator gives approximately 788 pieces for purchase.
Does the calculator deduct the gate opening?
Yes. Enter the number of openings, their combined width and average height. The calculated opening area is deducted from the gross CHB wall area.
Does a 4-inch and 6-inch CHB fence use the same number of blocks?
If the blocks have the same nominal face dimensions, the number needed to cover a given wall face area is essentially the same. Their thickness differs, but the calculator's block count is based on wall face area.
How much allowance should I add for CHB?
The calculator provides 0%, 5%, 10% and custom options. Five percent is the default preliminary allowance, but the appropriate quantity depends on the actual project and expected cutting or breakage.
How do I calculate the number of fence posts?
The calculator divides the total fence alignment by the selected maximum preliminary spacing and rounds the number of bays upward. For a straight continuous alignment, the preliminary regular post count is the number of bays plus one.
How many posts are needed for a 30-meter fence at 3-meter spacing?
A straight 30 m alignment divided into 3 m bays gives 10 bays and a preliminary count of 11 regular posts. Special gate and corner conditions must still be considered separately.
Is 3 meters the standard spacing for CHB fence posts?
The calculator uses 3 m only as a default preliminary quantity-planning option. It is not presented as a universal structural requirement. Actual spacing should follow the structural plans.
How do I calculate plastering area for a fence?
For one face, the plastering area is approximately equal to the net CHB wall area. For both faces, multiply the net CHB area by two.
Does the calculator estimate fence paint?
It estimates the approximate paintable wall area based on the selected finished faces, but it does not calculate paint liters. Use the dedicated Paint Calculator Philippines for paint quantity.
Does the calculator include mortar for CHB?
No. Use the dedicated CHB Calculator Philippines for a more detailed preliminary CHB and mortar estimate.
Does the calculator calculate fence footings?
No. Footing dimensions depend on the structural design and actual site conditions. The calculator intentionally avoids assuming footing dimensions.
Does the calculator calculate rebar for the fence?
No. Reinforcement size and spacing must come from the structural plans. Once those details are known, the Rebar Calculator Philippines can be used for quantity calculations.
Can I use this calculator for a retaining wall?
No. A wall retaining soil is subject to lateral earth pressure and requires appropriate structural design. This calculator is intended for preliminary quantity estimation of a CHB perimeter fence.
Can I use the result for final construction?
The result is a preliminary quantity estimate. Final material quantities and all structural details should be checked against the approved drawings, specifications and actual site conditions.