From room measurements to a buying plan: knowns and gaps
One sheet of measurements, needs and prices can prevent mismatched quantities before shopping. It is a reviewable first plan, not an engineering design or a contractor’s final quote.
Quantities come before totals
Floor area is length × width. Rectangular wall area is 2 × (length + width) × height, less openings; the ceiling is separate. Paint litres = net area × coats ÷ product coverage, plus your chosen reserve. Read one-coat coverage from the container.
Cooling needs context
LG publishes an initial 600–800 BTU/h per m² estimate. It is not a heat-load design for every climate. Sun, insulation, glazing, occupants and use can change the choice; discuss the range with an installer before buying.
References: LG — Preliminary room area and cooling capacity
Leave unknowns visible
A floor price per m² does not automatically include cutting waste or installation. Paint prices may exclude preparation and AC prices installation. Record these gaps and request them in the quote. A known-items subtotal is not a complete budget.
Example: a 5 × 4 m room
At 2.8 m high, walls total 50.4 m². Excluding 4 m², applying two coats at 10 m²/L and adding 10% reserve requires 10.208 L. Floor area is 20 m²; tile boxes and cuts need their own calculation.
Illustrative prices of 50 per floor m², 20 per paint litre, 2000 for the AC and 1000 labour total 4204.16 currency units. Remove the AC price and the known subtotal is 2204.16, not a free AC: the plan is still incompletely priced.