Worked examples at $25 a block
Blocks = wall face in square feet × 1.125, rounded up. Doors and windows are not subtracted, so the shed and garage lines lean high. These are block counts priced at $25 a block, not quotes for a kind of job.
| Wall | Blocks | At $25 |
|---|---|---|
| Garden wall, 30 ft long, 4 ft high30 × 4 ft = 120 sq ft | 135 | $3,375 |
| 100 sq ft of wall facefor example 25 × 4 ft = 100 sq ft | 113 | $2,825 |
| Privacy wall, 50 ft long, 6 ft high50 × 6 ft = 300 sq ft; 6 ft or lower: no NJ construction permit as a fence | 338 | $8,450 |
| Block shed, 10 × 12 ft, 8 ft walls44 ft around × 8 ft = 352 sq ft; door and window not subtracted | 396 | $9,900 |
| One-car garage, 12 × 24 ft, 8 ft walls72 ft around × 8 ft = 576 sq ft; a permit job; footing and slab not in the block count | 648 | $16,200 |
Why 1.125 blocks per square foot
A standard block is sold as 8×8×16 inches but made 3/8 inch smaller in each direction, 7-5/8 × 7-5/8 × 15-5/8. The 3/8-inch mortar joint brings each block back to an 8 × 16 inch space on the wall, 0.889 sq ft, so a square foot of wall takes 1.125 blocks (cinderblockscalculator.com). Buying the block yourself, that site adds 10% for half-block cuts at corners and breakage. The count also tells you how long the laying takes: Angi says a skilled mason can lay upward of 90 to 120 blocks a day.
What national guides say a block wall costs
Each figure below is that source's own, with its date. None of them is a New Jersey survey.
| Source and what it prices | Their figure |
|---|---|
| Angi (Sept. 21, 2026), block fence | $10–$30 per sq ft |
| Angi, garage or shed walls | $8–$40 per sq ft |
| Angi, foundation or basement walls | $10–$20 per sq ft |
| Angi, mason labor | $10–$17 per sq ft |
| Angi, standard 8×8×16 block, material only | $1.25–$2.50 each |
| cinderblockscalculator.com (Nov. 3, 2026), installed | $15–$30 per sq ft |
| cinderblockscalculator.com, material only | $5–$9 per sq ft |
| Family Handyman (July 13, 2025), concrete block fence | $9–$12 per sq ft |
Angi also breaks out the extras. Use them as a checklist when you compare written quotes:
| Extra | Angi's range |
|---|---|
| Delivery | $50–$200 |
| Permits (Angi's national range) | $50–$500 |
| Reinforcement, for walls that carry weight | $1–$5.25 per sq ft |
| Waterproofing sealant | $2–$10 per sq ft |
| Finishing (sealing and surface) | $1.50–$10 per sq ft |
| Capstones | about $0.95 more per block |
| Split-face blocks | $2.30–$3 per block |
Cinder block or concrete block?
Most people search for cinder block. What goes into most walls today is concrete block. Family Handyman explains the difference:
- Both are made with Portland cement. Concrete block uses sand and gravel; cinder block adds a lightweight material like cinders or volcanic pumice.
- True coal-cinder block has not been mass-produced for many years. Most of what is sold as cinder block today is concrete with pumice.
- Cinder block is a little more expensive and lighter to carry, but has less structural strength, and some building codes prohibit it for structural use.
- For a wall over 7 ft, Family Handyman says concrete block is the safer choice.
Do you need a permit for a block wall in New Jersey?
New Jersey's Uniform Construction Code (N.J.A.C. 5:23-2.14) answers it by what the wall is:
- A fence, 6 ft or lower: no construction permit. The exception does not apply to barriers around a swimming pool.
- A retaining wall, 4 ft or taller: a permit. The height is the total of every retaining wall on the same slope, measured from the bottom of the footing to the top of the wall. A lower retaining wall also needs one if it affects a foundation.
- A garden shed: no building permit if it is 200 sq ft or less, 10 ft or lower, accessory to a home, and has no water, gas, oil or sewer connection. Electrical work in it still needs an electrical permit.
- Part of a building: a garage, an addition or a foundation is construction, and the code makes it unlawful to build without first applying for and getting a permit.
The construction code is one office. Your town's zoning rules on where a wall or fence may stand and how tall it may be are a separate question, so ask the zoning office before you build on a property line.
Two more New Jersey rules before the digging
- Call 811 first. New Jersey law requires anyone digging, homeowners' contractors included, to call New Jersey One Call at least three full business days before work starts, wait for the marks, and hand-dig within two feet of any marked line (New Jersey One Call).
- The frost line is 3 ft in North Jersey. New Jersey's residential code sets the frost line depth at 3 ft 0 in for Mercer and Middlesex counties and every county north of them, Essex included, and 2 ft 6 in to the south (N.J.A.C. 5:23-3.21). That table is in the code for one- and two-family homes.
What to ask before you sign
- Is the price per block laid, or for the blocks only? A $2 block and a $25 laid block are not the same number.
- What is the footing, and is it in the price?
- Will the wall be reinforced, and how: rebar, filled cores, or both?
- What caps the wall, and is it sealed?
- Who calls 811, and who files the permit if the wall needs one?
- Is the contractor registered? Every home improvement contractor in New Jersey has a registration number for the contract. How to check it.
Mason block with AB in Essex County
Concrete and foundation block, brick steps, facades and retaining walls are our masonry work, for homes and commercial buildings. Our office is on Newark Avenue in Belleville, and we work across Essex, Union and Passaic counties. Retaining walls are a different block and a different price: Cambridge Sigma 8 segmental block at $40 per block, block included, on the masonry page.