100 Amp vs 200 Amp Service: Which Does Your Home Need?

For most homes in Woodstock, a 100 amp service is enough if you have gas heat, gas water heating, and no EV charger, while a 200 amp service is the right call for all-electric homes, houses over about 2,500 square feet, and any household adding a Level 2 EV charger or a heat pump. If your panel is a 100 amp unit and you are planning any of those upgrades, you need 200 amps. If you are already at 200 amps, you almost certainly do not need to go higher.

This guide walks through how to read your own panel, what the numbers actually mean, what a 200 amp service upgrade Woodstock GA costs in 2026, and when it is genuinely worth doing. We do this work every week across Cherokee County, so the numbers below are what we see on real jobs, not textbook estimates.

The Short Answer: 100 Amp vs 200 Amp Service in Woodstock GA

100 amp vs 200 amp service Woodstock GA comes down to total connected load, not house size alone. A 100 amp panel delivers 24,000 watts at 240 volts; a 200 amp panel delivers 48,000 watts. That doubling is the entire story.

Here is the practical split we use on estimates:

• 100 amps is fine for: homes under roughly 2,000 sq ft with gas furnace, gas water heater, gas range, and central AC. Typical 1970s-1990s construction.
• 200 amps is needed for: all-electric homes, houses over 2,500 sq ft, homes with two AC systems, tankless electric water heaters, Level 2 EV chargers, heat pumps, or any combination of those.
• 400 amps is rare here: large homes with two EV chargers, electric tankless plus heat pump plus shop equipment. We see maybe a handful a year in Woodstock.

If you are unsure which side of the line you fall on, an electrical panel inspection and load calculation Woodstock GA settles it in about an hour. We add up every major appliance, apply the NEC demand factors, and tell you the number.

What the Amp Rating Actually Means

The amp rating on your main breaker is the maximum current the service can deliver continuously before the main trips. Amps times volts equals watts, so a 100 amp service at 240 volts gives you 24,000 watts of usable capacity, and a 200 amp service gives you 48,000.

That capacity is shared across everything in the house at once. The lights, the fridge, the AC compressor, the dryer, the microwave, and the EV charger all pull from the same pool. When the pool runs dry, the main breaker trips and you lose the whole house.

Modern code uses a load calculation defined in NEC Article 220 to size that pool properly. It is not as simple as adding up nameplate ratings, because not everything runs at the same time. But it is also not as loose as some homeowners assume. A 100 amp service that was comfortable in 1985 with a gas dryer and window units can be badly undersized today with a heat pump, an induction range, and a 48 amp EV charger.

One more thing worth knowing: the panel and the service are two different things. A 200 amp panel on a 100 amp service is still a 100 amp service. The wire from the meter, the meter main, and the utility feed all have to match. That is why a real upgrade involves the service mast and meter main replacement Woodstock GA as well as the panel itself.

How to Tell Which Service Your Woodstock Home Has

You can usually identify your service in under two minutes without opening anything. Look at the main breaker at the top of the panel, or the label on the meter base outside.

1. Open the panel door (not the dead front). The main breaker is the large two-pole breaker at the top or bottom.
2. Read the number stamped on the breaker handle. It will say 100, 125, 150, or 200.
3. If the main breaker is not obvious, check the meter base outside. The amp rating is stamped on the tag.
4. If you see two separate panels side by side, you may have a split service or a subpanel setup, which changes the math.

Homes in Towne Lake and Eagle Watch are a mixed bag. The older sections built in the late 1980s and early 1990s are frequently 100 or 125 amp. The newer builds from the 2000s onward are almost all 200 amp. Downtown Woodstock has more 100 amp and even 60 amp fuse panels than most people expect, because the housing stock there goes back further.

If you cannot find the rating, or the label is worn off, do not guess. A licensed electrician can identify it in a few minutes and confirm whether the wire size matches the breaker.

How Do I Know If I Need 200 Amp Service in Woodstock Georgia?

You need 200 amp service in Woodstock if your load calculation exceeds 100 amps, if your main breaker trips when multiple large appliances run together, or if you are adding any of the loads below. These are the triggers we look for on every estimate.

• Level 2 EV charger: 32 to 48 amps continuous. That alone can consume half of a 100 amp service.
• Heat pump or electric furnace: 30 to 60 amps depending on size and backup strips.
• Electric tankless water heater: 60 to 120 amps. This one almost always forces a 200 amp upgrade.
• Electric range or induction cooktop: 40 to 50 amps.
• Two central AC systems: 30 to 40 amps each.
• Hot tub or pool heater: 30 to 50 amps.
• Workshop with welder or large compressor: 30 to 50 amps.

Add two or three of those to a typical house and you are past 100 amps even with demand factors. Add four and you are pushing 200.

There is also the nuisance-trip signal. If your main breaker trips when the AC kicks on while the dryer is running, that is not a coincidence. That is your service telling you it is full.

Should I Upgrade to 200 Amp Service in Woodstock GA?

Yes, upgrade to 200 amp service in Woodstock GA if you plan to stay in the home more than a few years and you are adding any large electric load. The upgrade is a one-time cost, and it is far cheaper than doing it later under pressure when a buyer's inspector flags it or when your EV charger install is blocked.

There are three situations where we tell homeowners to hold off:

1. You are already at 200 amps and nothing new is being added. Going to 400 is not worth it.
2. You are selling within 12 months and the home has no EV, no heat pump, and no electric tankless. A 100 amp service is not automatically a defect.
3. Your only issue is a single tripping circuit, not the main. That is a branch circuit problem, not a service problem.

For everyone else, the math favors upgrading. A 200 amp service upgrade Woodstock GA also unlocks options later: solar, battery backup, a generator interlock, a subpanel for a finished basement or garage shop. None of those are practical on 100 amps.

If you want a generator that runs the whole house during a winter outage, that conversation starts with the service size. We handle generator interlock and transfer switch installation Woodstock GA alongside panel upgrades all the time, and the two are much easier to do together.

What It Costs in 2026

Typical 2026 pricing in this area for a 100 to 200 amp service upgrade runs $2,400 to $4,800 for a straightforward overhead service, and $3,800 to $7,500 when the meter main, mast, or underground feed has to be replaced. The spread is wide because the panel is rarely the whole job.

What drives the number up or down:

• Panel only, same service size: $1,400 to $2,800. This is a replacement, not an upgrade.
• 100 to 200 amp overhead upgrade: $2,400 to $4,800.
• Underground service or long mast replacement: add $1,000 to $2,500.
• Permit and inspection fees in Cherokee County: $150 to $400 depending on scope.
• Utility coordination and disconnect/reconnect: usually included, occasionally billed separately by the utility.

If your home still has a fuse box, the conversion is a separate line item. A fuse box to breaker panel conversion Woodstock GA typically runs $2,000 to $4,500 on its own, and it is almost always paired with a service upgrade because the existing wiring and grounding rarely meet current code.

We give a flat price after we see the panel and the meter. No hourly surprises.

Do I Need 200 Amp Service for an EV Charger in Woodstock GA?

Not always, but usually. A 32 amp Level 2 charger needs a 40 amp dedicated circuit. On a 100 amp service, that circuit alone can push you over the load calculation once you account for the AC, range, and dryer.

There are three ways to handle it:

• Upgrade to 200 amps. Cleanest option. Full 48 amp charging, no compromises.
• Install a load management device. The charger throttles down when the house is near capacity. Works, but you charge slower on hot afternoons.
• Add a subpanel. Sometimes useful if the main panel is full but the service has headroom. A subpanel installation Woodstock GA can free up breaker space without touching the service.

We install EV charger installation Woodstock GA on all three setups. If you tell us the model of charger and the year your home was built, we can usually tell you over the phone whether a service upgrade is going to be required.

One note for Cherokee County homeowners: many HOAs here require the charger to be mounted inside the garage and the conduit run to be concealed. That affects labor, not the electrical math, but it is worth planning for.

What to Watch Out For

The biggest mistake we see is homeowners buying a 200 amp panel and assuming that makes the service 200 amps. It does not. The wire from the meter, the meter main, and the utility transformer all have to support the new rating. Swapping the panel alone is a code violation and a fire risk.

Other things to watch:

• Aluminum branch wiring. Common in 1960s and 1970s Woodstock homes. It needs special breakers or pigtailing, not just a new panel.
• Missing ground rods or bonding. Older services often have no grounding electrode system that meets current code. That gets corrected during the upgrade.
• Undersized service entrance conductors. If the existing wire is only rated for 100 amps, it has to be replaced, not reused.
• Double-tapped breakers. Two wires under one lug is a common shortcut and a real hazard.
• Federal Pacific or Zinsco panels. These have known failure issues and should be replaced regardless of amp rating.
• No AFCI or GFCI protection. Current code requires it in most living areas. We handle AFCI and GFCI breaker installation Woodstock GA as part of most upgrades.

We also see a lot of panels installed without a surge protector. A whole-home surge protection Woodstock GA device is a $300 to $600 add-on during an upgrade and it protects every circuit in the house. Doing it later costs more because the panel has to be opened again.

When to Call a Professional

Call a licensed electrician if you cannot identify your service size, if your main breaker has tripped more than once in the last year, if you see scorch marks or smell burning near the panel, or if you are planning any of the loads we listed above. These are not DIY problems.

We are Woodstock Electrical Panel Upgrade, and panel work is the only thing we do. Our team handles the load calculation, the permit, the utility coordination, and the inspection. You get a flat price and a clean install.

If you are in one of the older neighborhoods like Brookshire or Deer Run, we can usually tell you what service size is typical for your street before we even arrive. That saves a trip.

For a broader look at what we offer, see our Woodstock electrical panel upgrade page.

Frequently Asked Questions

What is the difference between 100 amp and 200 amp service in Woodstock GA?

A 100 amp service delivers 24,000 watts at 240 volts; a 200 amp service delivers 48,000. The 200 amp service supports larger electric loads like EV chargers, heat pumps, and electric tankless water heaters. Most Woodstock homes built before 1995 have 100 or 125 amp service.

How do I know if I need 200 amp service in Woodstock Georgia?

You need 200 amps if your load calculation exceeds 100 amps, if your main breaker trips when large appliances run together, or if you are adding an EV charger, heat pump, electric tankless water heater, or second AC system. A one-hour load calculation confirms it.

Can I upgrade from 100 to 200 amp service in Woodstock GA?

Yes. The upgrade takes one to two days and involves a new panel, new service entrance conductors, a new meter main, and a Cherokee County permit and inspection. Typical 2026 cost is $2,400 to $4,800 for an overhead service.

Is 200 amp service worth it in Woodstock?

Yes, if you plan to stay in the home and add any large electric load. The upgrade is a one-time cost that unlocks EV charging, heat pumps, and generator backup. If you are already at 200 amps and adding nothing, it is not worth going higher.

Do I need 200 amp service for an EV charger in Woodstock GA?

Usually yes for a 48 amp charger on a 100 amp service. A 32 amp charger with a load management device can sometimes work on 100 amps, but the calculation is tight. We can tell you over the phone with your charger model and home age.

Get Help with Electrical Panel Upgrade in Woodstock

If you are still not sure whether your home needs 100 or 200 amps, we will run the load calculation and give you a straight answer, even if the answer is that you do not need to upgrade yet.

Call Woodstock Electrical Panel Upgrade at (470) 742-0135 to schedule an inspection or get a flat-price quote on a 200 amp service upgrade.