Blast Door Load Calculator
Enter a peak reflected overpressure (or derive it from a charge + standoff preset) and the leaf area — and get the indicative total blast force (kN) on the door and an indicative class band. Indicative India 2026 only — a real blast door is engineered by a qualified blast/structural consultant.
Indicative only — not a design. Blast doors are project-engineered to ASCE / US ACI 370R (or equivalent) by a qualified blast/structural engineer using the actual charge, standoff, reflected pressure–impulse pair and dynamic structural response. This tool gives a back-of-envelope force and class band only. Never size, buy or sign off a blast door from this output.
Blast load
≈ 7.3 psi. Drag for a feel; type exact values for > 300 kPa.
Typical mid-range event; partly dynamic, partly quasi-static (DLF ~1.3). Leaf 1.2 × 2.4 m = 2.9 m². Force on leaf = overpressure × area (1 kPa = 1 kN/m²). Indicative India 2026 — confirm everything with a blast engineer.
Indicative total blast force on the leaf
0 kN
≈ 15 tonnes-force · 50 kPa over 2.9 m²
Indicative door-class band
Medium
Moderate threat. Reinforced leaf, multi-point bolting and a designed frame/anchorage system.
Overpressure
50 kPa
7.3 psi
Force on leaf
144 kN
press. × area
Design force*
187 kN
DLF 1.3
Force on the leaf vs overpressure at 2.9 m². Dot = your point; dashed lines = class boundaries (35 / 70 / 140 kPa). Indicative only.
Indicative class bands by peak reflected overpressure
A rough robustness tier only. Real classification (e.g. GSA / ASTM F2247 levels, or a project performance spec) is set by the blast engineer from the pressure–impulse pair, not pressure alone.
Low
0–35 kPa
Light blast / nuisance pressure. A hardened steel door with engineered anchorage may suffice.
Medium
35–70 kPa
Moderate threat. Reinforced leaf, multi-point bolting and a designed frame/anchorage system.
High
70–140 kPa
Serious threat. Heavy blast-rated assembly, dynamic-tested, with capacity-designed surround.
Severe
> 140 kPa
Severe / close-in threat. Bespoke blast door + structural surround; full dynamic analysis essential.
Brief a blast door the right way
DesignAI turns this indicative load into a vendor-ready question set — standard, rating, leaf build-up, frame anchorage and what your blast engineer must confirm.
Assumptions & method
*Force on leaf = overpressure × area. Because 1 kPa equals 1 kN/m², the indicative total static force is simply peak reflected overpressure (kPa) multiplied by leaf area (m²). The design force applies a crude dynamic load factor (DLF) for the chosen impulse band to hint at the dynamic amplification — a real design uses the pressure–impulse diagram and an SDOF/FE response, not a single DLF.
The charge + standoff presets give banded, illustrative TNT-equivalent overpressures only — they are not Kingery-Bulmash or UFC 3-340-02 design curves. Class bands (low <35, medium 35–70, high 70–140, severe >140 kPa) are an indicative robustness tier for early conversations.
These doors are project-engineered. Get a vendor spec and a qualified blast/structural engineer (to ASCE / US ACI 370R or equivalent) to size the leaf, frame, hinges and anchorage. Do not procure from this estimate.
Supply costs for blast-resistant doors in India run roughly ₹15,000–₹1,00,000+ per door (supply-only, before 18% GST), rising sharply for severe-band, certified or large openings. Add frame, anchorage, installation and GST.
Related Guides — Deep-dive reading
Blast-Resistant Doors: Overpressure Ratings & Cost India 2026
How blast-proof doors are rated by peak reflected overpressure, impulse and rebound — plus where they are used and what they cost in India.
Home Doors & EntrancesSpecialty Door Cost in India: Price Bands Guide (India 2026)
Indicative ₹ cost bands for fire, blast, bullet, lead, cleanroom, freezer, high-speed and other project-engineered doors in India.
Home Doors & EntrancesBallistic Door Standards in India: UL 752 & EN 1522 (2026)
A specifier's reference to ballistic door ratings — UL 752 levels 1-8 and EN 1522 FB1-FB7, the calibres each stops, and how to map an Indian threat to a class.
Home Doors & EntrancesRelated Tools — You may also find these useful
Acoustic Door STC Calculator
Work out the STC rating and door build — single leaf, drop seal or sound-lock — to hit your target noise level.
STC CalculatorBulk Door Order Estimator
Estimate a builder project door order with volume-discount tiers, city index and 18% GST.
Bulk EstimatorCity Door Price Comparison
Compare the same door across multiple Indian cities side by side and find where it is cheapest.
Price Comparison