Calculated result
2bags
Thinset bags to order
Formula
FLOOR-THINSET-001Length × width × (1 + waste) ÷ bag coverage
120 ft²
Tiled area
132 ft²
Area including waste
Flooring calculator
Thinset calculator
a 12 ft × 10 ft floor is 120 ft². With 10% waste and 90 ft² per bag, the order rounds to 2 bags. In metric, tiled area is 11.15 m².
Formula. Length × width × (1 + waste) ÷ bag coverage
Thinset or tile-mortar bag count from tiled area, selected trowel coverage and a visible mixing allowance.
By Feroz Sheikh · Formula FLOOR-THINSET-001 v1.0.0 · Tested formula
Formula
FLOOR-THINSET-001v1.0.0Project inputs
Enter your measurements. Switching units converts the same project, including coverage and unit rates. Package yields keep the unit printed beside each field.
Refine measurements and rates at any time. Your current values are included in the material-list PDF.
Planning estimate, not engineering advice. Confirm site measurements and product specifications. Calculation limits.
This calculator divides finished tile area plus a visible allowance by the coverage printed for the selected thinset bag and trowel notch.
- Measure the finished tiled area.
- Enter coverage from the selected bag at the actual trowel notch, including back-buttering when required.
- Keep grout, cement board and sealer on separate estimate lines.
Add your project costs
Enter supplier prices and any labour, equipment or delivery costs. Pick a currency — badges, inputs, and totals follow.
Costs use the carton or square-foot rate you type. Construclytic does not fetch store prices. Underlayment, grout, thinset and labour stay companion lines.
How this calculator works
A transparent tile thinset calculator takeoff.
Feroz SheikhWritten and reviewed by Feroz Sheikh · founder
This calculator divides finished tile area plus a visible allowance by the coverage printed for the selected thinset bag and trowel notch.
FLOOR-THINSET-001 counts bags from tiled area, the selected trowel’s coverage and a visible extra. A 1/4 in square-notch and a 1/2 in trowel do not share a bag. Grout is a different product.
Printed kilograms per square metre
Weber, LATICRETE and MAPEI notch rates, and the back-buttered rows for 30×30, 60×60 and 120×60, are in tile adhesive per square metre. Enter the coverage that matches the sheet. Do not add a second back-butter allowance when that row already includes it.
Worked example. Example: a 12 ft × 10 ft floor is 120 ft². With 10% waste and 90 ft² per bag, the order rounds to 2 bags.
See the example inputs and calculated result
This separate example uses the calculator's starting values in imperial units. It stays unchanged when you edit the tool above. Example rates, yields and dimensions are assumptions, not recommendations for your project.
| Input | Example value |
|---|---|
| Floor length | 12 ft |
| Floor width | 10 ft |
| Coverage per bag | 90 ft² |
| Waste factor | 10 % |
Example result: Thinset bags to order — 2 bags.
Length × width × (1 + waste) ÷ bag coverage
Use the labelled units above when reproducing this example. To work in metric, switch the calculator to Metric; applicable measurements are converted, while product-specific units remain labelled.
- 1. Measure the finished tiled area.
- 2. Enter coverage from the selected bag at the actual trowel notch, including back-buttering when required.
- 3. Keep grout, cement board and sealer on separate estimate lines.
Field notes that change the number
- Coverage is the bag and trowel you will use, not a universal 50 ft².
- Large-format tile and mortar-bed work eat more.
- Back-buttering is extra only when the coverage you entered does not already include it.
Common mistakes
- Using grout bags as thinset.
- Ignoring the trowel size on the bag.
- Treating this as a waterproofing membrane.
Need the broader workflow? Read the flooring planning guide.
How-to: Thinset bags: use the coverage for your product and trowel · Grout quantity: why tile size and joint width change the bags · How to order floor tile packages
Questions
Questions about tile thinset calculator
Does one bag always cover 90 ft²?
No. Coverage changes with notch size, mortar type and substrate. Use the selected product chart.
Does this include grout?
No. Use the tile grout calculator for joint volume. Thinset is the bonding mortar only.
What is the formula ID?
This thinset calculator publishes formula FLOOR-THINSET-001, version 1.0.0. The ID stays on the result and on the estimate line.