California density bonus calculator
Enter the base density and the affordable set-aside, and the calculator returns the bonus, the total units, the incentives and the parking cap under Government Code 65915.
The results appear here when the page's script loads.
An estimate for early studies; the City's planning staff confirm the numbers on the application.
How the calculator works
The calculator follows Government Code section 65915 as last amended by AB 87 (Stats. 2025, ch. 486), in force from January 1, 2026. Each result names the subdivision it comes from.
- Base density. The bonus is figured on the maximum allowable gross residential density on the date of application (subdivision (f)). Enter that figure with its fraction; the calculator rounds it up, because subdivision (q) rounds each component of the calculation, base density and bonus density alike, up to the next whole unit.
- The bonus percentage. Subdivision (f) sets a table for each income level. Very low income units earn 20 percent at 5 percent of the base units, rising to 50 percent at 15 percent. Low income units earn 20 percent at 10 percent, rising to 50 percent at 24 percent. Moderate income for-sale units earn 5 percent at 10 percent, rising one point per point to 35 percent at 40 percent, then to 50 percent at 44 percent. The tables move in whole percentage points, so the calculator reads the share down to the whole percent.
- 100 percent lower income projects. The bonus is 80 percent of the lower income units, and up to 20 percent of the units may be moderate income. Within one-half mile of a major transit stop or in a very low vehicle travel area, the project has no maximum density at all and may add up to three stories or 33 feet (subdivisions (f)(3) and (d)(2)).
- Incentives or concessions. One, two, three or four, rising with the affordable share (four at 16 percent very low income or 45 percent moderate income for-sale, subdivision (d)(2)(F)), and five for a 100 percent lower income project (subdivision (d)(2)(D)). Waivers under subdivision (e) are separate and do not count toward the number.
- Parking. Subdivision (p) caps what a city may require: one space for a studio or one-bedroom unit, one and a half for two or three bedrooms, two and a half for four or more. Near a major transit stop with unobstructed access, a project with at least 20 percent low income units (or 11 percent very low income units) is capped at 0.5 spaces per unit. A 100 percent lower income project has no parking requirement when it sits within one-half mile of a major transit stop with unobstructed access, when it is rental housing for residents 55 or older or special needs housing with paratransit or a fixed bus route that stops at least eight times a day within one-half mile, or when it is supportive housing (subdivision (p)(3)). The calculator rounds a fractional total up.
A worked example
A lot zoned for 40.0 units, with 15 percent of the base units set aside as low income:
| Step | Figure | Source |
|---|---|---|
| Base density | 40 units | subdivision (f) |
| Low income units at 15 percent | 6 units | subdivision (b) |
| Density bonus at 15 percent low income | 27.5 percent | table in subdivision (f)(1) |
| Bonus units, 40 times 27.5 percent, rounded up | 11 units | subdivision (q) |
| Total | 51 units | |
| Incentives or concessions | 1 | subdivision (d)(2) |
| Parking for 30 one-bedroom and 21 two-bedroom units | 62 spaces (30 plus 31.5, rounded up) | subdivision (p)(1) |
At 24 percent low income, the same lot reaches the 50 percent maximum: 20 bonus units, 60 in total, and three incentives.
What the numbers change in the set
The calculation is the first table a plan checker reads on a density bonus project, and every figure in it appears again elsewhere in the set: the unit matrix, the affordable unit schedule, the parking tabulation and the incentives and waivers table. The density bonus guide sets out each table and diagram the bonus puts on the sheets, and how a change in unit mix moves the parking count downstairs.
The calculator is a starting point for a test fit. TECTO Studio draws the base case and the bonus case side by side in your Revit model, with the density table and the unit matrix built as model schedules so the numbers update with the plan; see feasibility studies and test fits.
Limits of the estimate
- Local rules can be more generous than the state law, and the City of Los Angeles has its own incentive programs beside the state bonus.
- The second bonus under subdivision (v), for additional very low or moderate income units on top of a project already at 50 percent, is not in the calculator.
- Replacement units under subdivision (c)(3) can change the affordable count on a site with existing housing.
- For moderate income shares between 40 and 44 percent, check the step in the subdivision (f)(4) table before relying on it.
- The parking cap of 0.5 spaces per bedroom for a for-sale project with 40 percent moderate income units near transit (subdivision (p)(2)) is not modeled, because the tool groups two- and three-bedroom units together.
Sources
- California Government Code section 65915, as amended by Stats. 2025, ch. 486 (AB 87): subdivisions (b), (c)(3), (d)(2), (e), (f), (p), (q) and (v).
- TECTO Studio, What a California density bonus changes in the drawing set.