Overview

The Building Coverage & Floor Area Ratio Calculator computes Korea's two key building-density regulations from your land area, building footprint, and above-ground gross floor area. Building coverage ratio (BCR, 건폐율) measures how much of the lot the building footprint occupies, while floor area ratio (FAR, 용적률) measures total above-ground floor space relative to the lot. Enter the permitted limits for your zoning district and the calculator also works backwards to show the maximum buildable footprint and floor area, plus how much headroom remains.

Formula

BCR(%) = building footprint area ÷ land area × 100 (Building Act, Art. 55)
FAR(%) = above-ground gross floor area ÷ land area × 100 (Building Act, Art. 56)
Max footprint = land area × permitted BCR ÷ 100
Max above-ground floor area = land area × permitted FAR ÷ 100
e.g., land 330㎡, footprint 165㎡, floor area 495㎡ → BCR 50.0%, FAR 150.0%

How to Use

1. 1Enter the land (lot) area in square meters.
2. 2Enter the building footprint area (the largest horizontal projection, usually the ground-floor area).
3. 3Enter the above-ground gross floor area (sum of all above-ground floors, excluding basements and accessory parking).
4. 4Enter the permitted BCR and FAR for the zoning district to see compliance status and maximum buildable areas.

Examples

Background

BCR and FAR are defined in Articles 55 and 56 of Korea's Building Act, while the actual caps are set by Articles 84 and 85 of the National Land Planning and Utilization Act's Enforcement Decree, which give a range per zoning district that each municipality's urban planning ordinance then fixes. For example, the decree caps Type-2 general residential zones at 60% BCR and 100–250% FAR, and local ordinances such as Seoul's often set lower figures. Note that FAR excludes basement floors and accessory above-ground parking from the countable floor area, so it differs from the total gross floor area on the building register.

Tips

• ✔Permitted ratios vary by parcel. Check the zoning district on the government's Toji-eum land-use portal (eum.go.kr) and the municipal ordinance for the actual limits.
• ✔Basement floors do not count toward FAR — which is why basements are a common way to add floor space without consuming FAR.
• ✔Some elements (balconies up to 1.5m, eaves, canopies) are excluded from footprint calculations under the Enforcement Decree, so final design figures need an architect's review.
• ✔Lower BCR means more open yard space; higher FAR means more stories on the same land — both are core drivers of land value.

FAQ