Masonry calculator

Retaining wall block

SRW and garden-block count from exposed face area and the selected block face.

Reviewed formula · v1.0.0

Project inputs

Enter field measurements. Imperial lengths take feet and inches. Unit conversion happens before the reviewed formula is applied.

Wall lengthft + inExposed face lengthftinExposed heightft + inHeight above grade; buried course is extraftinBlock lengthinNominal block face lengthBlock heightinNominal block face heightWaste factor%Allowance for cuts and breakage

All values can be refined when you edit the estimate. This tool does not replace field verification or local requirements.

Calculated result

114blocks

Blocks to order

FormulaMAS-SRW-001

blocks = ceil(length × height ÷ (block length × block height) × (1 + waste))

96 ft²

Face area

108 blocks

Base block quantity

Transparent cost view

Planning rates only. Pick a currency — badges, inputs, and totals follow. Material is a rate. Labour is hours × a planning hourly rate. Equipment and delivery are this-job amounts.

Material ratePlanning · per calculated unit · USDEquipmentPlanning · this job · USDDeliveryPlanning · this job · USDLabour hoursPlanning · this jobLabour ratePlanning · per hour · USDOverhead %%Contingency %%Markup %%Tax %%

Planning defaults are office figures, not a bid. US ready-mix in 2026 often lands around $125–165 per cubic yard delivered; place-and-finish commonly $2–4 per square foot. Replace every rate with a supplier or crew quote before you send the letter.

Indicative FX as of Aug 2026. Planning conversion, not a live bank rate.

Material costUSD 9,690

Labour (8 h)USD 280

Direct costUSD 10,080

Overhead + contingencyUSD 1,008

Markup + taxUSD 1,331

Estimated project totalUSD 12,419

View estimate Quote / invoice Add another item

Embed this calculator

<iframe src="https://construclytic.com/embed/retaining-block" title="Retaining wall block" width="100%" height="820" loading="lazy" referrerpolicy="strict-origin-when-cross-origin" style="border:1px solid #d7e0da;border-radius:16px;background:#fff;"></iframe>

Paste on a contractor site or blog. The iframe is a planning takeoff, not a bid.

How this calculator works

A transparent retaining wall block takeoff.

This calculator divides exposed retaining-wall face area by the selected block face, then applies a visible cutting allowance.

Worked example. Example: a 24 ft × 4 ft exposed face using 16 in × 8 in blocks is 108 blocks before 5% waste, rounding to 114.

1. Measure exposed length and height, not buried base course.
2. Enter the actual block face, not a generic 8×16 if you are buying a different unit.
3. Add caps, geogrid and drainage stone as separate estimate lines.

Need the broader workflow? Read the masonry planning guide.

How-to: How to count CMU and brick

Questions

Questions about retaining wall block

Does this design the wall?

No. Setback, geogrid, drainage, surcharge and local requirements need independent review.

Is the buried course included?

No. Add one extra course if the base is buried, or raise the height input.

What is the formula ID?

This calculator publishes formula MAS-SRW-001, version 1.0.0. The ID stays on the result and on the estimate line.

Is this engineering advice?

No. Construclytic is a planning website, not a registered engineering or contracting firm. Field checks, codes and product data still sit with you.

Does Construclytic fetch live supplier prices?

No. Costs use the rate you enter. Construclytic does not fetch live supplier prices.