Automotive tools & calculators
Everything on this page is free, works on your phone and needs no account. Pick a tool and start immediately.
Diagnostics
8Interactive Car Diagnostic
Answer guided questions to narrow down why your car is behaving badly.
☆Air Conditioning Diagnostic
Step-by-step guide to find out why the AC is not cooling.
☆OBD-II Code Lookup
Search thousands of diagnostic trouble codes with causes and fixes.
☆OBD-II Live Scanner
Live RPM, speed, coolant and battery over Bluetooth with a BLE ELM327 adapter.
☆Photo Diagnostic Assistant
Photograph a tire, pad, disc or leak and follow an inspection checklist.
☆Sound Diagnostic Assistant
Record an engine noise and match it to likely causes.
☆Live OBD PID Data
Real-time engine data with charts — RPM, speed, coolant, MAF, load and battery analysis.
☆OBD Protocol Compatibility
Find which OBD protocol your vehicle uses — CAN, KWP2000, J1850 and more.
☆Electrical
2Battery Calculator
Estimate battery health from open-circuit voltage and estimate runtime.
☆Charging System Check
Analyze alternator and charging voltage with the engine off, idling and loaded.
☆Engine
8Oil Change Calculator
Oil quantity, service interval, filter and full service checklist.
☆Torque Specs Lookup
Search verified tightening torque values for common components.
☆Spark Plug Calculator
Replacement interval, cost and a quick misfire symptom assistant.
☆Cooling System & Coolant
Overheating diagnostic tree and coolant mix calculator.
☆Engine Compression Calculator
Theoretical compression ratio from bore, stroke and chamber volume.
☆Engine Builder Calculator
Displacement, piston speed and power estimates from bore and stroke.
☆Power & Torque Converter
Convert kW ↔ hp, Nm ↔ lb-ft and derive torque from power at RPM.
☆Oil Change Specs
Exact oil quantity, viscosity and filter for your car model and engine.
☆Brakes & Tires
3Tire Calculator
Decode tire sizes and compare two sets with speedometer impact.
☆Wheel Diameter Calculator
Total diameter, circumference and distance per revolution.
☆Brake Calculator
Disc thickness, pad wear alerts and replacement cost estimate.
☆Fuel & Economy
1Transmission
1Garage & Billing
13Garage Quote & Invoice Generator
Build professional estimates and invoices, then export as PDF.
☆Repair Cost Calculator
Real cost, margin and client price for any repair job.
☆Parts Margin Calculator
Set different margins for retail and professional customers.
☆Labor Cost Calculator
Time × hourly rate, plus parts and extras for the full bill.
☆Customer Manager
Client cards, linked vehicles and service history — stored only on your device.
☆Digital Service Book
VIN, mileage and full maintenance history per vehicle.
☆Service Reminders
Push notifications when an oil change or service comes due.
☆Vehicle Dashboard
A live status board per vehicle, computed from your service book.
☆Garage Dashboard
Revenue, accepted quotes, most profitable work and clients at a glance.
☆Parts Inventory
Track part stock with low-stock alerts and stock value.
☆Voice Assistant
“Create a quote for brake pads” — spoken commands become actions.
☆Photo → Quote
Photo of the car → confirm works → parts + labor → quote PDF.
☆Diagnostic Report Generator
Build a printable diagnostic report from a code or symptom with findings and checks.
☆Learn
6Maintenance Checklist
Interactive 10,000 km service checklist you can tick on your phone.
☆Mechanic Quiz
Test your automotive knowledge and learn with explanations.
☆Which Tool Do I Need?
Pick an operation and get the exact tools, steps and safety warnings.
☆Mechanic Training
6 levels of interactive lessons and quizzes — from fundamentals to advanced.
☆AI Mechanic Assistant
13 free AI tools: mechanic chat, OBD explainer, photo inspection, voice commands, trip planning and more.
☆Car Programming & Tuning
ECU tuning, module coding, keys/immobilizer, gains calculator, coding logbook and tuning glossary.
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Open the menu in your browser and choose "Add to Home Screen". AutoTools then launches full-screen like a native app and several tools keep working offline.
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