Four systems, four trades, four completely different ways of quoting the same sentence: “what will it cost to replace?” This page prices each of them the way the trade that does the work actually prices it - and gives you a band, not a number, because anyone who gives you a single number for a job they have not looked at is guessing.
Water heater replacement cost
The heater is priced as a unit, fitted. The published guides quote it that way and do not split the box from the plumber cleanly, so neither does the calculator - adding a separate labor line to these figures would charge you for the fitting twice.
The conversion is the whole price story. A like-for-like swap is a morning’s work. A conversion is a different job wearing the same name: a tankless burns hard enough to need a bigger gas line and cannot reuse the old tank’s vent, and moving between gas and electric means either running a gas line or pulling a dedicated 240 V circuit. That is why one neighbor paid $1,200 and the other paid $5,000, and why the calculator makes you say which one you are doing.
Water softener cost
A softener is priced the same way as the water heater above: as a unit, fitted. The guides quote it installed and do not split the tank from the plumber cleanly, so the calculator does not either. The one thing that moves the number most is whether your home already has a softener loop plumbed in near the water main - if it does not, adding one is a real line item, not a hidden markup.
Salt-based or salt-free is the first decision, and they are not the same machine. A salt-based ion-exchange softener actually removes the calcium and magnesium, regenerates itself with salt, and is rated in grains of hardness it can strip between regenerations. A salt-free “conditioner” removes nothing - it changes the way the minerals crystallise so they are less likely to scale - so it burns no salt, wastes no water regenerating, and has no grain rating at all. It costs more up front and less forever after, and it is the option to reach for where a salt-based system’s brine discharge is restricted.
What size water softener do I need? Size a salt-based unit to your household and your water, not to the biggest tank on the shelf. The rule of thumb: people in the house × the water each uses a day (about 75 gallons) × your hardness in grains per gallon = the grains it has to strip each day, and you want a unit that carries roughly a week between regenerations. A family of four on moderately hard water - about 10 gpg, or 170 mg/L - lands on a 32,000 to 48,000 grain unit. Oversize it and it regenerates too rarely to keep the resin bed healthy; undersize it and it regenerates too often and wears out early.
Water softener installation cost on its own - the labour, when you have bought the unit separately - runs about $500 to $1,500 where a loop is already plumbed in, and a plumber quoting a straightforward swap is often near the low end. A first-time install with no loop, or one that needs a drain run and a dedicated outlet, is where the bill climbs, and it is why the same “installation” quote can vary by a thousand dollars. A confident DIYer with an existing loop can do it for the price of the fittings.
A Culligan water softener cost is a dealer quote, not a shelf price. Culligan and the other dealer-installed brands (Kinetico, EcoWater) are sold and fitted by local dealers who set their own pricing, and they often lead with a rental - roughly $30 to $50 a month - rather than a purchase. Expect a bought dealer system to sit at or above the top of the salt-based band above, the trade-off being local service and a longer warranty than a box-store unit carries. Get the dealer’s buy price and the rental terms in writing, and price both against a unit you fit yourself before you sign anything.
HVAC replacement cost
Cooling is quoted by the ton and heating by its BTU output - so that is what the calculator computes first, and then prices.
Read the AC column again, because it is telling you something. The price per ton falls as the box gets bigger - about $3,100-4,300 a ton at 1.5 tons, about $1,400-1,900 a ton at 5 - because a big slice of the job is the same work whatever hangs off the end of it. That is why the calculator reloads the rate when the size changes instead of pretending one $/ton figure covers the range. Efficiency moves the same rate: an 80% AFUE furnace is $3,800-6,200 installed where a 96%+ one is $7,500-12,000, and a SEER2 13.4 condenser is $5,300-7,900 where a 20+ one is $11,400-17,300.
And the sizing estimate is a rule of thumb, not a design. It exists here to get you a price. The size that actually gets installed comes from a room-by-room load calculation - Manual J in the US, CSA F280 in Canada - and ACCA’s own figures show real load calculations average nearer 1,400 sq ft per ton than the 500 the rule uses. The rule of thumb systematically oversizes, and an oversized air conditioner is a worse air conditioner: it satisfies the thermostat before it has run long enough to dehumidify, then shuts off. Cold and clammy is what oversizing feels like.
Sewer line replacement cost
Pipe is quoted by the linear foot - except a spot repair, which is quoted by the job, because the plumber is charging for the dig, the cut and the splice whatever the bad section measures.
Trenched or trenchless? The surface decides, not the pipe
This is the one place on the page where a small piece of geometry settles an argument people have badly. Take a 40 ft run, a 2 ft trench:
Open cut: 40 ft × $50/ft = $2,000 of pipe
40 × 2 = 80 sq ft of surface torn up
Pipe bursting: 40 ft × $60/ft = $2,400 of pipe
2 access pits ≈ 39 sq ft of surface torn up
Under a lawn ($2/sq ft to resod):
open cut $2,000 + $160 = $2,160 ← the trench wins
bursting $2,400 + $78 = $2,478
Under a concrete driveway ($10/sq ft to break out and replace):
open cut $2,000 + $800 = $2,800
bursting $2,400 + $390 = $2,790 ← trenchless wins
Trenchless is not “better.” It costs more per foot and buys you less digging, and whether that is a bargain depends entirely on what is lying on top of your pipe. Under grass it is money wasted. Under a driveway, a mature garden or a city street it is money saved - and under a street it may not even be your call.
The street cut is the one number nobody publishes. No national cost guide gives a rate, because there is no national rate: your municipality sets its own restoration fee. Los Angeles, to give the only real anchor we could verify, charges $8.24 per sq ft on a local street and $19.44 on a designated one. Yours will be different. Ask before you budget.
Electrical panel upgrade cost
Panels are priced by the amperage tier, plus the service entrance, plus the circuits. It is the thinnest computation of the four - and that is honest, because it is how the job is actually quoted.
Two warnings on this one. A 400 A “panel” and a 400 A service are different jobs - the band above is the panel swap, and a genuine 400 A service upgrade that brings a new mast, meter and utility work with it can run several times higher. And the utility disconnect and reconnect is a real fee that nobody publishes, because your power company sets it. Ask them, not a cost guide.
How this calculator works
Every figure on this page is a real quantity times a real contractor rate. Nothing else. The five systems differ only in what the quantity is:
Water heater = heater installed + conversion work + extras
Water softener = softener installed + extras
HVAC tons = floor area ÷ (floor area per ton) → nearest size BUILT
BTU/h = floor area × (BTU per sq ft) → next furnace UP
cost = tons × $/ton + BTU/h × $/1,000 BTU + ducts + extras
Sewer pipe = run length × $/ft (open cut, bursting, lining)
= one repair × $/repair (spot repair)
area = run × trench width (open cut - the whole run)
= 2 access pits (pipe bursting)
= 1 access point (CIPP lining)
cost = pipe + area × $/sq ft of surface + extras
Panel = panel at that amperage + circuits × $/circuit + extras
Then every one of them becomes a band:
low = quantity × your low rate
high = quantity × your high rate
typical = the midpoint of the two
Note the two rounding rules, because they go in opposite directions and both are deliberate. Cooling rounds to the nearest size actually built (and there is no 4.5 ton unit - the line goes 4, then 5), because an oversized condenser is a worse machine. Heating rounds up, because a furnace that cannot make the design day is simply not big enough, and there is no 64,000 BTU furnace on the shelf - the next one is 80,000.
The typical is the midpoint of your own band, not a fourth estimate pulled from somewhere else, so the answer is only ever as precise as the rate you gave it. The math runs in exact metric internally, so switching units changes the displayed numbers and never the answer.
Rates are indicative 2026 US contractor ranges from published cost guides - HomeGuide and Angi for HVAC and ductwork, Fixr and This Old House for water heaters, Angi and Quality Water Treatment for water softeners, HomeAdvisor for sewer lines, and This Old House for panels. They move with your city, your access and your contractor’s diary, and they are not a quote. The calculator seeds its rate fields from exactly these numbers so you can overwrite them the moment you have a real estimate in hand.
Worked example
This example follows the unit system you pick in the calculator above.
A 2,000 sq ft house replacing both the furnace and the AC:
- Cooling: 2,000 sq ft ÷ 500 sq ft per ton = 4 tons → a 4 ton unit. (There is no 4.5 ton; the line goes 4, then 5.)
- Heating: 2,000 sq ft × 40 BTU/h per sq ft = 80,000 BTU/h → an 80,000 BTU/h furnace.
- Cooling: at $1,625-2,200 per ton installed (the published band for a 4 ton unit, divided by its 4 tons) = $6,500 - $8,800.
- Heating: at $64-119 per 1,000 BTU/h = $5,120 - $9,520.
- Ducts reused, permit $100-250. Band: $11,720 to $18,570, typical about $15,145 - the midpoint, not a separate guess.
- Then get a load calculation. If it comes back at 3 tons rather than 4 - and it often does - you have just saved $700 or so and bought a system that actually dehumidifies.
Codes, efficiency floors and money where you are
In the United States, the size of the system is not supposed to come off the square footage at all. The standard is
ACCA Manual J, and the IRC requires it by name - section M1401.3 says equipment shall be sized to Manual S based on loads calculated with Manual J, not off the square footage. ACCA is blunt about what the shortcut costs you: real load calculations average nearer 1,400 sq ft per ton than the 500 the rule of thumb uses, so the rule of thumb routinely sells people a system that is too big.
Use the estimate above to price the job and to sanity-check a quote - then make the contractor do the load
calculation before anyone orders equipment.
On the furnace: an 80% AFUE furnace is still legal to buy, so mid-efficiency versus high-efficiency is a genuine choice you have to price. The DOE rule that raises the floor to 95% applies to furnaces manufactured on or after 18 December 2028, and it is in litigation - do not assume it will be there when you buy (the rule itself).
On the panel: the NEC sets a flat floor - a one-family dwelling gets no less than a 100 A service, whatever the size of the house (230.79(C)). That is a minimum, not a target: an all-electric house with a heat pump and a car charger is the reason 200 A is the job most people actually do (source).
On the water heater: the DOE standards finalised in 2024 bite on water heaters manufactured on or after 6 May 2029, and their practical effect is that most electric storage heaters over 35 gallons will have to be heat-pump units. It does not affect what you can buy today, but it is worth knowing before you replace like for like (source).
On public money: the federal 25C tax credit for heat pumps and heat-pump water heaters is GONE - it was repealed in July 2025, and the IRS will not allow it for any property placed in service after 31 December 2025. The placed-in-service date is what counts, so a heat pump bought in 2025 and installed in 2026 gets nothing. What remains is the state-administered DOE Home Energy Rebates, and several states have already exhausted their allocation - check your own state programme before you budget for a dollar of it (source).
On the sewer line, there is no national rule to give you - and that is the finding, not a gap.
Who owns the lateral is set by your municipality. Some cities own the pipe from the main to your property line
and will fix their half; others make you responsible for the whole run, including the length of it buried under
the public street. That single question can double the job, so ask your city before you budget, not after the
camera goes down the pipe.
Before you spend anything
- Make them quote the unit, not just the job. A sewer contractor pricing “the job” and one pricing $/ft cannot be compared until you know his run length. Ask for the rate and the quantity separately - then this calculator will tell you whether the two multiply out.
- Get the load calculation before anyone orders equipment. It is the cheapest part of an HVAC job and the only part that decides whether the expensive parts were the right size.
- Check what is above the sewer line before you accept a method. The pipe is half the bill; the driveway is the other half.
- Find out who owns the lateral. Some cities maintain it to your property line, others hand you the whole run to the main including the length under the street. That answer can double the job.
- Do not budget on a tax credit without checking it still exists. The US federal 25C credit was repealed for anything placed in service after 31 December 2025, and Canada’s Greener Homes Grant is closed. What is left is state and provincial, and some of it is already out of money.
- Replace the system, not the symptom. A new furnace hung off leaking ducts, or a new panel fed by a failing service mast, is money spent twice.
