This estimates quantities, it doesn't specify type: large format/exteriors usually need higher class + back-buttering per data sheet and design.

What trowel size for large format?

Bigger notch for bigger tiles, plus back-buttering outdoors. Consumption rises with notch size — set yours in the calculator.

How many bags for 215 sq ft?

At 4 kg/m² (≈0.8 lb/ft²) a 20 m² (≈215 sq ft) job needs 88 kg with waste: 4 × 25 kg bags (or 4 × 50 lb). Adjust to your trowel.

Is grout sold by the bag too?

Yes: it's estimated by weight per joint and rounded up to bags, like thin-set.

Can I see pounds instead of kilos?

Yes — switch to Imperial: 4 kg/m² shows as ≈0.8 lb/ft² and bag weights convert to lb.

Adhesive & grout calculator

Thin-set bags from trowel/format consumption and grout by joint. All with waste and bag rounding.

Purchase quantity

88 kg

Net measurement: 80 kg · Waste 10 %

Net adhesive80 kg
25 kg adhesive bags4 bag
Net grout10 kg
5 kg grout bags3 bag

Use my prices

Your prices per language/currency. Used when you enable “Use my prices” in calculators. My prices →

Calculate labour, margin & GST

Shopping list

What to buy for this calculation. Look up each material at your store.

25 kg adhesive bags · 4 bagSearch at Amazon
5 kg grout bags · 3 bagSearch at Amazon

How it's calculated (visible formula)

kg = area × consumption; bags = ceil(kg × (1+waste) ÷ bag)

Net geometric measurement, no waste.
Adjustable waste % for cuts and breakage.
Purchase rounded up to sellable units (boxes, bags, buckets, boards).

See methodology and formula versions

Worked example: 20 m², 8 mm trowel

Adhesive 4 kg/m² → 80 kg net
+10% → 88 kg
25 kg bag → 4 bags

→ 4 adhesive bags + grout per joint (see breakdown).

Common mistakes

One consumption for every format (large format needs more).
Forgetting back-buttering outdoors.
Ignoring uneven screeds.

From calculation to quote

Add labour, overhead and your margin, and generate the professional PDF.

Create quote Calculate margin & GST

FAQs

Which adhesive type?: This estimates quantities, it doesn't specify type: large format/exteriors usually need higher class + back-buttering per data sheet and design.
What trowel size for large format?: Bigger notch for bigger tiles, plus back-buttering outdoors. Consumption rises with notch size — set yours in the calculator.
How many bags for 215 sq ft?: At 4 kg/m² (≈0.8 lb/ft²) a 20 m² (≈215 sq ft) job needs 88 kg with waste: 4 × 25 kg bags (or 4 × 50 lb). Adjust to your trowel.
Is grout sold by the bag too?: Yes: it's estimated by weight per joint and rounded up to bags, like thin-set.
Can I see pounds instead of kilos?: Yes — switch to Imperial: 4 kg/m² shows as ≈0.8 lb/ft² and bag weights convert to lb.

Maintained by Srikanta M · Formula v1.0.0 · Verified 2026-09-10 · Updated 2026-09-10 · Limits: quantity estimation, not structural design or site supervision.