Auto Glass Repair vs Replace Decision Calculator
Determine whether your windshield or auto glass damage should be repaired or fully replaced based on damage characteristics, location, and cost analysis.
Formula & Scoring Model
The calculator uses a weighted multi-factor scoring model to produce a Repair Favorability Score:
Repair Score = Σ(Factor Scores)
Factor Scores:
Damage Type Score : Chip/Star = +3/+2; Crack = 0; Combination = -1; Floater = -2; Edge = -3
Size Score : ≤ threshold = +3; ≤ 2× threshold = 0; > 2× threshold = -3
(Threshold: 1 in for chips/stars; 6 in for cracks)
Location Score : Center/Top = +3; Passenger = +2; Peripheral = -1; Edge Zone = -3; Critical View = -4
Crack Count Score : 1 = +3; 2 = +1; 3 = -1; >3 = -3
Depth Score : Outer layer = +3; Unknown = 0; Inner layer = -4
Vehicle Age Score : 4–8 yrs = +2; 0–3 or 9–15 yrs = +1; >15 yrs = -1
ADAS Score : ADAS present = +2 (repair avoids recalibration cost)
Cost Ratio Score : Savings ≥ 70% = +2; ≥ 40% = +1; < 10% = -1
Cost Ratio (%) = (Replacement Cost − Repair Cost) / Replacement Cost × 100
Effective Replacement Cost = min(Replacement Cost, Deductible) + ADAS Recalibration Cost
(If Deductible ≥ Replacement Cost: Effective = Replacement Cost + ADAS Cost)
Savings = Effective Replacement Cost − Effective Repair Cost
Decision Thresholds:
Score ≥ 8 → REPAIR (High Confidence)
Score 3–7 → REPAIR (Moderate Confidence)
Score 0–2 → REPAIR Borderline (Consult technician)
Score -1 to -4 → REPLACE Borderline (Consult technician)
Score ≤ -5 → REPLACE (High Confidence)
Any Hard Disqualifier → REPLACE (High Confidence)
Hard Disqualifiers (auto-replace regardless of score):
• Edge crack (structural failure risk)
• Inner layer penetration (structural integrity lost)
• Damage in driver's critical view zone (optical distortion from resin)
• Damage within 2 in of windshield edge
• More than 3 impact points
• Size > 2× repairability threshold
Assumptions & References
- Chip/bull's-eye repair threshold of 1 inch diameter follows the National Windshield Repair Association (NWRA) and Repair of Laminated Automotive Glass Standard (ROLAGS).
- Crack repair threshold of 6 inches is the standard industry limit; some advanced resin systems extend this to 12 inches but with reduced optical clarity.
- The driver's critical view zone is defined as the area swept by the primary wiper blade directly in the driver's line of sight (approximately a 12-inch band centered on the driver's eye point).
- Edge cracks within 2 inches of the windshield perimeter compromise the urethane seal and structural bonding — replacement is universally recommended.
- ADAS recalibration cost estimated at $150–$300 (midpoint $225) based on industry averages; actual cost varies by vehicle make/model.
- Many insurance companies waive the deductible for windshield repair (not replacement) to encourage repair over replacement — verify with your insurer.
- Inner-layer penetration in laminated glass (which consists of two glass layers bonded by a PVB interlayer) means the structural integrity of the windshield is compromised and repair resin cannot restore it.
- References: NWRA Standards, ROLAGS (Repair of Laminated Automotive Glass Standard), AGRSS (Auto Glass Replacement Safety Standard), AAA Auto Glass Guide.