On-Street Parking Calculator

Example data table

Formula used

• Restricted length = (2 × intersection clearance) + (driveways × driveway width) + (hydrants × hydrant clearance) + (bus stops × bus stop length) + other no-parking length
• Available curb = total curb − restricted length
• Net curb for stalls = available curb − (2 × end buffer)
• Parallel module = stall length + maneuver allowance
• Angled module ≈ (stall width ÷ sin(angle)) + stripe allowance
• Spaces = floor(net curb for stalls ÷ module), adjusted for reserved accessible modules
• Parking lane area = available curb × lane width

How to use this calculator

1. Measure the curb segment length you can legally allocate to parking.
2. Enter setbacks for intersections, driveways, hydrants, and transit stops.
3. Select the parking layout and enter stall dimensions from your standard.
4. Add end buffers for transitions, tapers, signs, and curb ramps.
5. Reserve accessible spaces if required by your project scope.
6. Click Calculate to view results and download reports.

Planning notes for construction teams

Curb length inputs and constraints

Start with the measured curb segment that can legally host parking. Deduct constraints first: intersection setbacks at both ends, driveway openings, hydrant clearance zones, and transit stop lengths. These items can dominate the available curb. Logging each restriction as a quantity and a per‑item length makes field verification easier and supports permit discussions with reviewers.

Choosing parallel versus angled layouts

Parallel parking typically fits constrained streets because it needs less roadway width, but each stall consumes more curb length. Angled parking can increase space count on long frontages when the roadway can support the maneuvering geometry and the chosen angle. Use 45° and 60° as common planning cases, then compare results with your standard drawings and site turning movements.

Module length and space yield

The calculator converts curb length into “modules” that represent one space along the curb. For parallel layouts, the module is stall length plus a maneuver allowance that reflects real-world entry and exit. For angled layouts, the curb module is derived from stall width divided by the sine of the selected angle, plus a small striping tolerance. Smaller modules yield more spaces, but only if they remain buildable.

Accessible reservations and site compliance

If your plan must reserve accessible spaces, treat them as a share of the total capacity and apply the curb length your jurisdiction requires per accessible module. This tool reserves those spaces inside the computed total and checks whether the combined standard and accessible lengths still fit the available curb. Pair the output with curb ramp locations, sidewalk widths, and signage constraints to confirm constructability.

Using exports for construction documentation

Exporting the report helps track assumptions across design iterations. Use the CSV to compare multiple scenarios, such as different clearances, alternative stall sizes, or a temporary bus stop relocation. The PDF is useful for submittals, coordination with traffic control plans, and meeting notes. Always validate the final layout against local codes, striping standards, and current field conditions before mobilization.

FAQs

1) Why do intersection clearances reduce spaces so much?

Clearances apply at both ends, so the setback is doubled. On short segments, that removes a large share of usable curb, leaving fewer full stall modules that can fit.

2) Should I enter driveway width as curb cut or property opening?

Enter the effective no-parking length along the curb needed for safe turning. If your local rule requires extra buffer beyond the curb cut, include that additional length.

3) How is angled parking space length computed?

The curb module is estimated as stall width divided by sin(angle), then a striping allowance is added. It approximates how much curb each angled stall consumes, which limits total count.

4) Does lane width affect the number of spaces?

No. Lane width is used only to estimate parking-lane area for planning and documentation. Space count depends on available curb length and the selected stall module.

5) What should I use for accessible module length?

Use the curb length your standard detail requires for an accessible space, including any buffer that occupies curb. When uncertain, use a conservative larger value and verify with code requirements.

6) My field layout yields fewer spaces than the estimate—why?

Real sites include taps, trees, curb ramps, utility covers, and signs that add small restrictions. Increase end buffers and “other no-parking” length to match field conditions.