Well Drilling Cost Calculator: Build Your Own Estimate

Short answer

A useful well drilling cost estimate is your expected depth times the quoted drilling rate, plus casing priced per foot, plus every lump-sum item a working well needs: grouting, development, yield testing, the pump system, pressure tank, water line, electrical work, permits and a water test. Add a high scenario for a deeper hole. This calculator does that math with your own quoted numbers.

Most contractors charge for drilling by the foot, so depth drives the largest line.
Contractors estimate depth from local experience and cannot promise exactly where water will be found.
A drilling-only figure is not the cost of water at the tap: pump, tank, line and electrical work are separate lines.
Agree a maximum depth in writing; it sets the top of your realistic range.

Sources checked October 2026. General guidance; confirm local rules.

Interactive estimate

Build your estimate from your own quotes

Enter the figures from a written quote (or two). Leave a line blank if it is not part of your project. The calculator shows each line's math so you can check it against the proposal.

Drilling

Expected depth (feet)

Drilling rate ($ per foot)

From the written quote. Some drillers price by depth bands; use the rate for your expected band.

Casing

Casing length (feet)

Casing rate ($ per foot)

Casing is often priced separately from drilling. Length depends on geology and local code.

Quoted lump sums

Dollar amounts for items priced as a whole. Leave blank if not included.

Mobilization / rig setup ($)

Grouting and sealing ($)

Screen, drive shoe or other materials ($)

Well development and yield test ($)

Pump, drop pipe, wire and controls ($)

Pressure tank and fittings ($)

Trenching and water line to the house ($)

Electrical connection ($)

Permit, notice or registration fees ($)

Water quality test (certified lab) ($)

Water treatment, if needed ($)

Other quoted items ($)

Uncertainty

Maximum depth you would approve (feet)

Contingency (% of subtotal)

The high scenario re-prices drilling at your maximum depth, then adds contingency. Extra casing in loose ground is not predictable from depth alone, so cover it in contingency or ask the driller for a figure. Agree the maximum depth in writing before drilling starts.

Your estimate

Enter at least one figure to see a total. JavaScript is needed for live math; the formula below works by hand.

Estimate line items and the math behind each
Item	Math	Amount
No figures entered	—	—
Base estimate	Sum of lines	—
High scenario	Max depth + contingency	—

This is arithmetic on the numbers you entered, not a quote, an average or a prediction. Depth, geology, access and local rules can change the real cost.

The formula

Base estimate = (expected depth × drilling rate) + (casing length × casing rate) + every quoted lump sum.

High scenario = [base estimate + ((maximum depth − expected depth) × drilling rate)] × (1 + contingency ÷ 100). If you leave maximum depth blank, the high scenario only adds contingency.

This well drilling cost calculator works with the numbers from one or more written quotes. It multiplies per-foot items, adds lump sums, and shows a base estimate next to a high scenario built from the maximum depth you would approve. It does not supply prices: a calculator that invents a local rate would only give you false precision.

How do you use the well drilling cost calculator?

Start with the quote. Copy the drilling rate and the expected depth the contractor wrote down. Most contractors charge for drilling by the foot, which is why depth drives the cost of drilling and piping. Water Systems Council: Determining the Depth of a Well
Add casing separately. Contract guidelines from the National Ground Water Association (NGWA) recommend itemizing drilling per foot and casing per foot, with the casing diameter and thickness stated. NGWA: Guidelines for Written Contracts
Enter each lump sum the quote lists. Leave blank anything the quote does not include, then ask the contractor whether that item is excluded or simply missing.
Set the high scenario. Enter the maximum depth you would approve and a contingency percentage you can justify.

Which line items belong in a complete estimate?

A written, itemized estimate is the recommended starting point. A Montana well-owner guide lists the kinds of items an estimate can break out: equipment mobilization, drilling per foot, casing per foot, sealing materials and labor, screen or drive shoe, development, pump testing, grouting, the pump and accessories, disinfection and testing. Montana DNRC well-owner guide (revised 2007) [MT-DNRC source note]

Line How it is usually priced What to confirm in writing — comparison worksheet
Line	How it is usually priced	What to confirm in writing
Drilling	Per foot	Expected depth, depth bands, and what happens past the estimate
Casing	Per foot	Diameter, material, wall thickness, length
Grouting and sealing	Lump sum or per foot	Material and method used to seal around the casing
Development and yield test	Lump sum or hourly	Test length and what the written report will show
Pump system	Lump sum	Pump, drop pipe, wire, controls and installation
Pressure tank	Lump sum	Tank size and fittings
Water line and electrical	Lump sum or per foot	Trench length, who does the electrical work
Permits and fees	Fixed fees	Which office, which fee, who files
Water test	Lab fee	Which tests and which certified lab

Why does depth set the cost range?

Depth is the biggest unknown. Contractors base estimates on what experience shows is an average depth for your area, and a contractor cannot tell you exactly how deep to go to reach water. If the water first reached is adequate, drilling can stop there. Water Systems Council: Determining the Depth of a Well [WSC-DEPTH source note]

That uncertainty is why the high scenario matters. The Montana guide recommends setting a maximum depth the driller cannot exceed without your express agreement, with any extra drilling agreed in writing. Montana DNRC well-owner guide (revised 2007) Enter that same maximum here to see what it could cost. [MT-DNRC source note]

How do you compare two quotes with the calculator?

Run the calculator once for each written quote, then compare the results line by line rather than total to total:

Same depth, different rates. If both drillers expect the same depth, the per-foot rates and casing assumptions explain most of the gap.
Different depths. If one driller expects a much deeper well, ask why. Check the depths in nearby well reports; see how deep a residential well should be.
Missing lines. A quote that leaves out the pump, tank or water line will look cheaper. Add those lines from the other quote, or ask the bidder to price them, so you compare complete systems. Complete well installation cost lists every component.
Different high scenarios. Compare the maximum depth each driller will agree to in writing and the per-foot rate past the estimate.

Print each estimate and keep it with the quote checklist. The calculator clears when you leave the page; nothing is stored.

What can't a well drilling cost estimate tell you?

The output is arithmetic on your inputs. It does not know your geology, whether the hole will produce enough water, what your water test will show, or what your local permit office charges. It also cannot settle who pays if the well comes up dry; that is a contract question to resolve before drilling starts.

Before you sign, compare offers line by line with the quote checklist, and read the complete well installation cost breakdown to make sure no part of a working system has been left out.

Common questions

Why doesn't this calculator show average well drilling prices?

Rates vary by region, geology, depth band, rig type and season, and national averages hide those differences. The only numbers that describe your project are written quotes from contractors who have looked at your site, so the calculator asks you to enter them.

What should I use for expected depth?

Use the depth the contractor wrote on the quote, which is usually based on nearby wells and local experience. Ask what they assumed and check nearby well reports where your state publishes them. Then enter a maximum depth you would approve as the high scenario.

Is casing included in the per-foot drilling price?

Sometimes, but often not. Industry contract guidelines recommend itemizing drilling per foot and casing per foot separately, along with casing diameter and wall thickness. If your quote combines them, enter the combined rate as drilling and leave casing blank.

How much contingency should I add?

There is no standard percentage. Base it on what is uncertain in your quotes: unknown depth, possible extra casing in loose ground, treatment that a water test may require, or access work. The high scenario shows how much each assumption moves the total.

Does the calculator save or send my numbers?

No. The arithmetic runs in your browser. Nothing you type is stored, submitted or sent anywhere, and the clear button empties every field.

Is this a water well drilling cost calculator or a pump calculator?

It covers the whole water well project: drilling, casing, sealing, development and testing, plus the pump, pressure tank, water line, electrical work, permits and water testing. Leave out any line your project doesn't include.

Sources & claim context

Citations mark where guidance is grounded. They are general resources dated on retrieval, not guarantees for any property, project, price, licensure, permit or yield. No expert, attorney or reviewer signoff is claimed by this site.

Montana DNRC well-owner guide (revised 2007) · MT-DNRC · accessed 2026-10-10
https://dnrc.mt.gov/_docs/water/waterwelldrillowner.pdf
Historical Montana document; do not nationalize its licensing, bond, permit, yield, pricing or legal clauses; refresh with current local authority
Water Systems Council: Determining the Depth of a Well · Water Systems Council (wellcare) · accessed 2026-10-10
https://www.watersystemscouncil.org/download/wellcare_information_sheets/basic_well_information_sheets/Determining-the-Depth.pdf
Undated industry sheet; typical-range figures are not a prediction for any property
NGWA (Wellowner.org): Guidelines for Written Contracts · NGWA · accessed 2026-10-10
https://wellowner.org/basics/planning-for-a-water-well/guidelines-for-written-contracts/
Does not prescribe who pays for a dry hole

Claims are grounded in the dated source notes above; project-specific price, yield, licensure and permit answers require site-specific and local verification.

Well drilling cost calculator