A wheelchair ramp starts with geometry, not a price per metre
A common planning mistake is to measure only the entrance step and then compare short portable-ramp prices.
A 0.60m vertical rise needs 7.20m of horizontal ramp run at the normal Korean building-ramp slope of 1:12.
Start and end activity spaces, intermediate landings, clear width, rails, slip-resistant finish, foundation, and external drainage can require substantially more room and money.
This calculator converts a finished-level rise and a target 1:N slope into horizontal run, true sloping length, flight count, landing count, activity-space area, and an indicative site envelope.
It then multiplies those quantities by quotations that you enter and keeps foundation, drainage, canopy, professional review, contingency, and VAT visible.
The result is a measurement and quotation brief, not a Korean permit, Barrier-Free certification, accessibility approval, or structural design.
Korea jurisdiction and rule date
The statutory values come from Article 2 and Attached Table 1 of the Enforcement Rule under the Korean accessibility convenience act.
The current rule record is ID 007970, MST 285263, promulgated April 1, 2026 and effective July 2, 2026.
Attached Table 1 serial 18078323 was checked through the National Law Information Center on August 18, 2026.
Applicability still depends on the facility, use, size, work type, and the competent authority.
Current Korean ramp dimensions used by the calculator
Item 12 of Attached Table 1 contains the detailed building-ramp dimensions.
The table below separates a normal requirement from a conditional relaxation or an optional feature.
Meeting one row does not establish complete compliance because access routes, doors, corridors, toilets, fire safety, structure, and site approvals can also apply.
Korean wheelchair-ramp values from Attached Table 1 effective July 2, 2026| Item | Current value | How this planner treats it |
|---|
| Normal building-ramp slope | 1:12 or gentler | The default slope preset |
| Conditional existing-facility slope | As steep as 1:8 | Always produces an exception warning and a four-condition check |
| Normal clear width | At least 1.2m | Measured inside rails, kerbs, or side walls |
| Conditional existing-building width | As little as 0.9m | Only a screening value; the work and space-hardship conditions must be confirmed |
| Rise between landings | No more than 0.75m | The rise is divided into flights of 0.75m or less |
| Activity space | At least 1.5m × 1.5m | Added at the start, end, every bend, and every intermediate landing |
| Two-side handrail trigger | Length 1.8m or rise 0.15m | Triggered when either threshold is met |
| Horizontal rail extension | At least 0.3m at each end | Included in the indicative two-side quantity |
| Surface | Level and slip resistant | A separate editable finish quantity can be included |
| External roof or canopy | May be installed | Shown as an optional confirmed cost, not a mandatory price |
The 1:8 option is not a small-site shortcut
The Korean table permits 1:8 only when all stated conditions are met: the ramp is in an existing rather than new facility, its height is no more than 1m, the facility structure makes 1:12 difficult, and the facility manager or another provider supplies permanent assistance.
Selecting 1:8 in this calculator only exposes the resulting geometry and the legal questions.
It does not decide that the relaxation is available or safe for a particular user.
How the ramp formulas work
Horizontal run and sloping length
For a slope written as 1:N, horizontal run equals vertical rise multiplied by N.
True sloping length equals the square root of horizontal run squared plus rise squared.
The calculator uses horizontal run for layout and true length for surface and rail quantities.
Percentage and angle
Slope percentage equals 100 divided by N.
Angle equals arctangent of 1 divided by N.
A 1:12 slope is about 8.33% and 4.76 degrees, but 1:N and required run are usually easier to verify on site.
Flights and landings
Minimum flight count equals the ceiling of rise divided by 0.75m.
A straight layout has one fewer intermediate landing than flights.
A successive 90-degree layout uses at least two flights because a direction change requires an activity-space landing even for a low rise.
Areas and rails
Sloping area equals true sloping length multiplied by clear width.
Each start, end, bend, or intermediate landing contributes a 1.5m by 1.5m planning area.
The rail estimate uses both sides, true sloping length, intermediate landing length, and 0.3m extensions at both ends of each side.
What the indicative envelope means
For a straight route, the planner adds every 1.5m activity-space length to the total horizontal ramp run and uses at least 1.5m for envelope width.
For successive 90-degree turns, flights alternate between X and Y axes and each axis receives the associated activity spaces.
The calculator checks both the original and a 90-degree rotated placement against the entered site dimensions.
It does not model columns, irregular boundaries, door swings, rail projections, foundations, drains, or the smallest possible switchback design.
Worked example: a 0.60m rise at 1:12
Assume a 0.60m finished-level rise, normal 1:12 slope, 1.20m clear width, and a straight layout.
Horizontal run is 0.60×12, or 7.20m.
True sloping length is approximately 7.225m and sloping surface area is approximately 8.67m².
Because the rise is no more than 0.75m, there is no intermediate landing, but start and end activity spaces remain part of the space check.
Worked wheelchair-ramp example for 0.60m rise and 1:12 slope| Output | Value | Meaning |
|---|
| Horizontal ramp run | 7.20m | Rise multiplied by 12 |
| True sloping length | About 7.225m | Quantity basis for ramp surface and rails |
| Intermediate landings | 0 | Rise remains within the 0.75m flight limit |
| Start and end spaces | 2 spaces, 4.50m² | Both remain clear activity spaces |
| Straight indicative envelope | 10.20m × 1.50m | Run plus two activity-space lengths |
| Handrail trigger | Yes | Both the 1.8m length and 0.15m rise thresholds are exceeded |
Why a 9m site can still be too short
The 7.20m sloping run fits within 9m, but the 10.20m straight planning envelope does not.
Do not solve this by changing 1:12 to 1:8 without the four existing-facility conditions.
Review a compliant bend, a vertical wheelchair lift, or a different accessible entrance with the competent authority and qualified designer.
Straight and successive 90-degree layouts
When a straight ramp is easier
- A detached-house yard has a genuinely clear long route.
- Landings do not obstruct doors, parking, escape paths, or public passage.
- Foundation, drainage, and rail details can follow one axis.
- The user can move without repeated direction changes.
When bends need investigation
- The frontage is short but clear space can be distributed across two directions.
- A rise above 0.75m already requires an intermediate landing.
- A boundary, parking bay, pavement, or column blocks a straight route.
- Every bend can retain a full 1.5m by 1.5m activity space.
The turn layout is deliberately an indicative successive 90-degree path, not an automated construction drawing.
A compact switchback has different inner-rail, wheelchair turning, drainage, and structural details.
Even when total area appears sufficient, an irregular shape or a narrow passage between columns may make the route impossible.
Transfer the calculated dimensions onto a measured sketch before requesting a site quotation.
Build the budget from comparable quotations
Korean accessibility law does not publish a nationwide statutory wheelchair-ramp construction price.
Material, anchorage, foundation, removal, access, welding, coating, drainage, waterproofing, lifting, night work, and reinstatement can change the total materially.
For that reason every market-price input starts at KRW 0.
Geometry remains available immediately, while a warning prevents a zero budget from appearing to be a real quote.
- Separate ramp and landing scope. Confirm whether the square-metre ramp price includes frame, deck, coating, edges, transport, and installation, and whether existing start or end floors need work.
- Normalize the rail unit. The calculator multiplies a per-metre price by an indicative two-side length. If a supplier gives one fixed two-side package price, enter it as another confirmed fixed cost instead of counting it twice.
- Remove anti-slip duplication. Clear the separate anti-slip switch only when the main ramp price expressly includes a suitable finish over the relevant surface.
- Expose ancillary work. Enter foundation and removal, external drainage, canopy, design or structural review, permit or accessibility checks, lifting, and service relocation separately.
- Use one VAT basis. Add 10% only when all entered quotation amounts are pre-VAT. Turn it off when the figures already include Korean VAT.
Contingency is editable, not a statutory rate
The 10% initial contingency is a transparent planning assumption for an early, incomplete scope.
Replace it with the project contract and risk allowance after drawings and trade scope are confirmed.
Only the 10% VAT setting is anchored to Article 30 of the Korean Value-Added Tax Act, MST 276117, effective January 2, 2026.
The calculator does not determine input-tax recovery, accounting classification, or whether every supplier line is taxable.
Step-by-step use
- Measure finished-level rise. Use the vertical difference between final departure and arrival surfaces, not an assumed number of steps.
- Choose slope and clear width. Start with the normal building-ramp values of 1:12 and 1.2m. Use 1:18 as a gentler comparison, not as permission to mix access-route rules without review.
- Enter unobstructed site dimensions. Exclude door swings, columns, meters, signs, parking bays, public pavement, boundaries, drains, and any route that cannot remain clear.
- Compare layout results. If both orientations fail, investigate a compliant route or lifting alternative rather than silently steepening the ramp.
- Enter written quotation values. Match the displayed areas and rail length to each supplier quantity and normalize VAT, exclusions, and fixed ancillary work.
- Use the output as a question sheet. Send the flight dimensions, landings, site shortfalls, warnings, and cost breakdown to the competent authority, designer, and contractors.
Practical scenarios
Detached-house entrance
Map the gate, parking manoeuvre, and storm-water path as well as the yard length. An existing level start or end surface may carry a zero construction unit price, but it must remain an unobstructed activity space.
Leased retail unit
Separate landlord consent, public-pavement occupation, door work, reinstatement, storage, and trading downtime. A portable ramp still requires product-load, anchorage, storage, assistance, and legal-substitution review.
Clinic or welfare facility
Review wheelchair, walker, stroller, and visual-access routes together. Check automatic-door detection, call assistance, lighting, handrail continuity, emergency movement, and maintenance responsibilities.
High rise with narrow frontage
Flight and landing counts grow quickly as rise increases. If even a turn layout fails, compare a vertical wheelchair lift or another entrance rather than assuming the conditional 1:8 slope is available.
Site-measurement checklist
- Vertical rise between final finished surfaces and any drainage fall.
- Continuous clear width inside rails, kerbs, or walls.
- Door swing and accessible handle approach space.
- Columns, utility meters, pipes, panels, signs, and projections.
- Property boundary, public pavement, road, and parking conflicts.
- Storm-water direction, drains, thresholds, and winter ice points.
- Ground and existing-slab condition for foundation design.
- Safety of the 0.3m horizontal rail extensions.
- Wheel interaction with a 50mm kerb or side wall.
- Canopy, lighting, cleaning, inspection, and snow-removal duty.
- Temporary access and trading or residential interruption.
- Permit, report, and accessibility-review authority.
Frequently asked questions
Does 1:12 mean that every ramp is 12m long?
No. It means 12m of horizontal run for each 1m of vertical rise. A 0.30m rise requires 3.60m of run and a 0.60m rise requires 7.20m, before activity spaces are added.
Can I select 1:8 whenever the site is small?
No. The current Korean table states four cumulative conditions: an existing facility, height no more than 1m, structural difficulty achieving 1:12, and permanent assistance from the manager or another provider.
Is a 0.9m clear width always accepted?
No. It is a conditional relaxation for specified work to an existing building when securing 1.2m is difficult. Confirm both the work category and hardship with the competent authority.
Why is a 1:18 option available?
It is a gentler planning target and matches the normal access-route slope in Item 1. This calculator conservatively retains Item 12 ramp widths and activity spaces, but the legal route classification and landing rules still require site review.
Can existing level floors have a zero landing price?
Yes for cost planning when no work is required, but keep the spaces in the geometry. Confirm repair, anti-slip finish, drainage, and obstruction scope in the written quotation.
Does a portable ramp avoid the building-ramp rules?
The calculator cannot make that conclusion. Confirm product load, length, anchorage, edge protection, slip safety, storage, assistance, and whether the device legally substitutes for the required facility.
Is the displayed budget an average Korean installation price?
No. Every construction price starts at zero and the result uses only values you enter. No nationwide market average is embedded because material and site scope vary greatly.
Does a green result guarantee Korean BF certification?
No. BF certification and accessibility conformity review examine the wider facility, drawings, and site. This tool organizes preliminary ramp geometry and cost questions only.
Official sources and update boundary
- National Law Information Center, current Enforcement Rule: ID 007970, MST 285263, effective July 2, 2026.
- Attached Table 1, detailed structure and material standards: serial 18078323, including access-route Item 1 and ramp Item 12.
- Ministry of Health and Welfare accessibility-facility overview: policy-level cross-check for ramps and rails.
- Accessibility Act ID 000186, MST 267429, Articles 8 and 9, effective December 21, 2025.
- Enforcement Decree ID 004627, MST 281167, Article 4 and Attached Table 2, effective January 2, 2026.
- Value-Added Tax Act ID 001571, MST 276117, Article 30, 10% rate effective January 2, 2026.
The legal records and attached table were rechecked on August 18, 2026.
Future maintenance must update the requirements, constants, tests, Korean content, and this English content together if slope, width, landing, rail, applicability, or VAT rules change.
Construction prices should remain user-entered rather than becoming stale code constants.
Create a dimension sheet before asking for a site price
Enter the rise, genuinely available space, target slope, clear width, and matched quotation inputs.
Take the resulting flight, landing, rail, shortfall, and cost tables to the Korean authority, designer, and at least two contractors so that every proposal covers the same route.