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Automotive Calculators

Suspension Load Calculator

2026-09-27 6 min

Dynamic corner load and spring force from sprung/unsprung weights and G load.

Dynamic Corner Load
2250 lb
Total through the contact patch
Spring Force
2000 lb
Sprung share only

Calculator

Corner Sprung Weight(lb)
lb
Corner Unsprung Weight(lb) Help
lb

Wheel, tire, brake, hub share

Bump Load(g) Help
g

1 = static, 2-3 = hard bump

Results update live as you type

Live statistics

Dynamic Corner Load

2250 lb

Total through the contact patch

Spring Force

2000 lb

Sprung share only

Results

Optimal

Dynamic Corner Load

2250lb

Total through the contact patch

Spring Force

2000lb

Sprung share only

Planning estimate from standard automotive formulas. Validate with dyno, timeslip or datalog data when precision matters.

Visualizations

Results overview

2,250Dynamic Corner Load
2,000Spring Force

Dynamic Corner Load vs. Corner Sprung Weight

Dynamic Corner Load

2,250lb
05,000

Formula

Scales corner mass by bump G — the load case for springs, stops, bearings and studs.

Dynamic = (sprung + unsprung) x G

Alternative Form

Springs carry sprung mass; tires/bearings carry everything

Variables

SymbolNameUnitDescription
GBump loadg1 static, 2-3 severe

Explanation

A 900-lb corner at 2.5 g is 2,250 lb of instant load — bump stops, bearings and studs live in this math.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Record the inputs.

Corner Sprung Weight:800 lb
Corner Unsprung Weight:100 lb
Bump Load:2.5 g
Result: 3 inputs ready
Step 2

Apply the formula.

Dynamic = (sprung + unsprung) x G
Result: Primary result = 2250 lb
Step 3

Read every derived output.

Dynamic Corner Load:2250 lb
Spring Force:2000 lb
Result: Dynamic Corner Load = 2250 lb
Final Answer
2250

Worked Examples

See how the calculator works with different scenarios.

Scenario

Curb strike / pothole hit.

Inputs

Sprung:800 lb
Unsprung:100 lb
G:2.5

Calculation

Dynamic = 2,250 lb; spring = 2,000 lb

Result

2,250-lb instantaneous corner load.

Interpretation

Bump stops must absorb the spring share beyond coil bind.

Understanding Your Result

Your Result: Dynamic Corner Load: 2250 lb

What This Means

Peak loads the corner hardware must survive.

Why It Matters

Sizes bump stops, bearings, studs and spring travel against real hits.

Professional Interpretation

Treat the primary result as a planning estimate, then validate on a dyno, at the track, or with logged sensor data. If measured numbers disagree by more than ~10%, re-check inputs (units are the usual culprit) before changing parts.

Recommendations

  • •Double-check units on every input before trusting the result
  • •Compare against the worked example below to sanity-check magnitude
  • •Validate with measured data (dyno, timeslip, datalog) when it matters

Learn — fuel economy, deeply

Corners see multiples of static weight in bumps.

1 · Where the gallon goes (energy path)

Engine heat

60–70% lost

Coolant + exhaust carry most energy away. Hybrids recover some via Atkinson cycle + regen.

Driveline

5–15% lost

Transmission, differential, accessories. CVTs and 8–10 speed autos lose less.

Aero drag

∝ v²

Doubles from 55→78 mph. Roof boxes hurt more than trunks.

Rolling + brakes

10–20%

Tires, weight, stops. Regen braking (hybrid/EV) reclaims city braking energy.

4 · Measure like a pro (the 3-tank protocol)

  1. Fill to first click at the same pump, record the odometer (Tank 0).
  2. Drive normally for 2–3 tanks; always refill to first click at the same pump.
  3. MPG = total miles ÷ total gallons across all tanks — averaging kills pump-click noise.
  4. Cross-check with the trip computer; a persistent >10% gap means the computer needs calibration — or the car needs service.
  5. Log with an OBD-II dongle for per-trip MPG if you want to isolate commute vs. highway behavior.

Practical Tips

  • •Design stops for 3 g, not 1
  • •Light wheels cut unsprung load directly
  • •Torque studs for dynamic, not static, loads

Common Mistakes

Mixing units (inches with mm, psi with kPa)
Convert every input to the unit shown on its field before calculating.
Trusting a single output blindly
Cross-check with the worked example and, when it matters, a dyno or datalog.

Assumptions

This calculator makes the following assumptions to provide estimates:

Steady-state model: Formulas assume stabilized conditions; transients, heat soak and traction limits are excluded.
Standard factors: Empirical constants (BSFC, VE, drivetrain loss) use typical values — your combination may differ.

Limitations

Be aware of these limitations when using this calculator:

Estimate, not measurement: Predictions carry real-world scatter of roughly ±5–15% depending on the model.
No transient effects: Shift time, wheelspin, spool lag and heat soak are not modeled here.

Frequently Asked Questions

Answers to common questions about this calculator.

How many G is a pothole hit?
2-4+ g at the wheel for sharp hits — brief but violent. Progressive stops earn their keep here.
Sprung vs unsprung weight?
Sprung rides on springs (body); unsprung (wheels/brakes) follows the road. Light unsprung improves response.

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Related Guides

Deepen your understanding with these educational resources.

Glossary

Technical terms used in mortgage calculations explained in plain language.

MPG
Miles per gallon. Distance travelled per gallon of fuel; higher is better. US gallon = 3.785 L.
L/100 km
Litres consumed per 100 kilometres; lower is better. Standard metric efficiency unit.
MPGe
Miles per gallon-equivalent. EV metric: miles travelled on 33.7 kWh (energy of 1 gal of gasoline).
CAFE
Corporate Average Fuel Economy — US fleet-average efficiency standard enforced by NHTSA.
Rolling resistance
Energy lost deforming tires as they roll. Low-pressure or wide tires raise it.
Aerodynamic drag
Air resistance growing with the square of speed — why highway MPG falls fast above 60 mph.
Hypermiling
Driving techniques (coasting, steady speed, anticipation) that maximise real-world MPG.
OBD-II
On-board diagnostics port. Scanners and dongles read live MPG, fuel trim and fault codes.

Authoritative References

Trusted sources and standards referenced by this calculator.

Applicable Standards

EPA Fuel Economy Testing (40 CFR Part 600)CAFE — Corporate Average Fuel Economy Standards (NHTSA)WLTP — Worldwide Harmonised Light Vehicle Test ProcedureSAE J1321 / J1711 — Fuel consumption test proceduresISO 2575 — Road vehicles symbols & efficiency markings

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