Dave Kuhn
Installation Specialist · Electrical installation, Gas line sizing
Published · 6 min read
Cooktop installation is the phase of a kitchen project where money gets wasted and schedules slip. Twenty years of field experience distilled: what you need to verify before you buy, what a contractor actually needs to do, and where the code gotchas hide.
For choosing the right cooktop in the first place, see how to choose a cooktop. For the induction case specifically, our best induction cooktops 2026 round-up has details, and the 240V circuit guide for induction covers the electrical-side deep-dive. Converting from an existing gas cooktop? Our gas to induction conversion guide walks through the full project.
The 10-minute pre-purchase checklist
Before you click Buy or walk into a showroom:
- Measure your cutout (length × depth) with a tape measure. Write it down.
- Photograph your breaker panel. Count free slots.
- Find your main service rating (typically 100 A, 150 A or 200 A — stamped on the main breaker).
- Find the gas meter if you have one; identify which appliances tap off which lines.
- Take a photo of the cabinet below the existing cooktop (depth, junction box location).
- Note the ventilation: CFM rating on the hood, size of the exhaust duct.
Do this and you’ll save your contractor 45 minutes at the first visit.
Electrical requirements by cooktop type
Induction cooktops
Almost all built-in induction cooktops require 240 V dedicated circuit, sized per the nameplate:
| Cooktop size | Typical load | Circuit breaker | Wire size |
|---|---|---|---|
| 24” induction (4 zones max 7,200 W) | 30 A @ 240 V | 30 A 2-pole | 10/3 AWG |
| 30” induction (most, 7,400–11,000 W) | 40 A @ 240 V | 40 A 2-pole | 8/3 AWG |
| 36” induction (flagship, 11,000–16,800 W) | 50 A @ 240 V | 50 A 2-pole | 6/3 AWG |
Always cross-check with the specific product’s installation manual. Bosch Benchmark 36” units want 50 A; Samsung 36” units often want 40 A. The differences matter.
Gas cooktops
Most gas cooktops need a standard 120 V, 15 A outlet for the ignition system and control electronics. Wall-mounted, in the cabinet below the cooktop. 2-ft cord is typical.
No 240 V circuit needed — which is a real install-cost advantage vs induction, offset partially by needing a gas line.
Electric coil and ceramic cooktops
Same requirements as induction: dedicated 240 V / 30–50 A circuit.
Gas line requirements
If you’re installing gas:
- 1/2-inch black iron or CSST corrugated stainless tubing is standard.
- Shutoff valve directly behind the cooktop, accessible without removing the unit.
- Flex connector from the shutoff to the cooktop (36-inch max length typical).
- Pressure test at 1.5× working pressure for 30 minutes (required by IRC).
Never DIY a gas line. Hire a licensed plumber or gas-fitter. Permit cost $60–$250 depending on jurisdiction; labor $150–$400 for a straightforward tie-in.
Cutout dimensions (the measurements that actually matter)
Nominal vs actual cutout is a constant source of confusion. Typical values:
| Nominal size | Typical cutout (W × D) | Counter depth needed |
|---|---|---|
| 24” | 22 1/4” × 18 3/8” | 20” minimum |
| 30” | 28 9/16” × 19 3/4” | 20” minimum |
| 36” | 34 9/16” × 19 3/4” | 20” minimum |
| 45”/48” | varies — always verify | 22” minimum |
Always download the specific model’s cutout template from the manufacturer’s site before cutting. Off by 1/16” is enough to require a countertop repair.
Countertop clearance and side walls
IRC Code and most appliance manuals require:
- At least 1 inch between cooktop and any combustible side wall, or noncombustible at the same plane.
- At least 30 inches from the cooktop surface to the bottom of a wood cabinet above (higher for some pro-style gas units — 36” is common).
- Cabinet below needs the depth called out on the spec sheet plus clearance for junction boxes.
Venting and makeup air
Ventilation requirements vary by cooktop type:
| Cooktop type | Minimum recommended hood CFM | Code trigger for makeup air |
|---|---|---|
| Induction 30” | 300 CFM | 400 CFM (IRC 2021) |
| Induction 36” | 400 CFM | 400 CFM |
| Gas sealed 30” | 400 CFM | 400 CFM |
| Gas sealed 36” | 600 CFM | 400 CFM |
| Gas pro-style 36” (open burner) | 900 CFM | 400 CFM |
| Downdraft (replaces hood) | 500 CFM | 400 CFM |
If your hood pushes more than 400 CFM, you’ll need makeup air — a dedicated duct bringing outside air in to replace what the hood pushes out. This is a code requirement in most US jurisdictions since 2009 IRC, and gets more strict every cycle.
Permits (do not skip)
A licensed contractor will typically pull one of:
- Electrical permit for circuit upgrades ($60–$200).
- Plumbing/gas permit for gas line work ($80–$250).
- Mechanical permit for hood replacement pushing >400 CFM ($60–$150).
DIY in most jurisdictions is legal for appliance replacement (same-spec swap) without a permit. Any wiring, gas line or venting change almost always needs one. Skipping permits voids homeowner insurance on any resulting damage.
The contractor walkthrough: what to ask
When a contractor comes to quote:
- “Will the existing circuit/wire gauge support this cooktop’s load?” (If no, what’s the fix?)
- “Is there enough space in the breaker panel, or do we need a subpanel?”
- “What’s the permit strategy?”
- “Will the hood CFM trigger makeup air?”
- “Can we keep the existing cutout, or will the countertop need modification?”
- “What’s your guaranteed lead time, and what’s the penalty if it slips?”
A good contractor will have ready answers. A bad one will hand-wave.
Typical install cost ranges (2026 US)
| Work | Typical cost |
|---|---|
| Drop-in induction swap, same circuit | $250–$450 |
| Induction + new 240 V circuit | $700–$1,300 |
| Induction + new circuit + subpanel | $1,500–$3,500 |
| Drop-in gas swap, same gas line | $300–$500 |
| Gas + new gas line run | $600–$1,200 |
| Gas + line + new 400 CFM hood + makeup air | $2,000–$4,500 |
| Pro-style gas with 900 CFM hood + makeup air | $3,500–$7,000 |
Add 25–30 % for high-cost markets (SF Bay Area, NYC, Boston).
Common code gotchas
- GFCI/AFCI requirement for 240 V kitchen circuits varies by code year and jurisdiction — some 2020 NEC jurisdictions require it; older don’t. Check before you buy.
- Gas line pressure testing is often required even for “simple” tie-ins. Don’t let a contractor skip this.
- Hood downdraft clearance to the cooktop surface is a very specific 6–10 inch window; mounting too high or too low fails inspection.
- Countertop material behind a gas cooktop can require heat shielding if within specific distances — check the spec sheet.
When to DIY, and when not
DIY is reasonable when:
- Drop-in, same-fuel-type, same-circuit replacement.
- You’ve pulled a cooktop before and know your panel.
- Your jurisdiction doesn’t require a permit for appliance-swap.
Call a pro when:
- Any new circuit, subpanel or service upgrade.
- Any gas line work at all. Ever.
- Hood upgrade pushing past 400 CFM.
- New construction or full remodel.
Bottom line
A cooktop install done right is boring — measured cutouts, correct circuit, proper shutoff, permit pulled, inspection passed. A cooktop install done wrong is an insurance claim, a house fire, or a cooktop that throttles because the circuit can’t feed it.
Spend the time in the pre-purchase checklist. Pull the permit. Hire the licensed person for anything beyond a drop-in swap. Your future self will thank you.
Dave Kuhn is a licensed electrician and gas-fitter in Colorado, NEC and IFGC certified. See his full author page for background.
