DIY vs Hire Bathtub Installation: Save or Hire a Pro?

What does a $240.00 DIY win mean?

On the defaults — a $450 tub, $80 of supplies, 6 hours at $55 an hour and a $1,100 pro quote — the DIY cost is $860.00 and DIY wins by $240.00. The DIY cost is the tub price plus the supplies plus your hours at your hourly value: $450 + $80 + 6 × $55 = $860.00. The win is the pro cost minus the DIY cost — if the win is positive, DIY wins by that much; if the win is negative, hiring wins by that much; if the win is zero, it is an exact tie. A $240.00 saving is real money, but it is not the whole story: a pro carries insurance, guarantees the tub does not leak, and takes the risk of a drain that will not seal and a tub that will not level. DIY wins on price; hiring wins on risk. This calculator prices the money — you price the risk.

Three things about the model are worth stating plainly.

First, there is no division here — this is addition and multiplication, not a ratio: $450 + $80 + 6 × $55 = $860.00. Second, the meaning is two hundred and forty dollars saved by fitting the bathtub yourself — the price of your time, not the price of the tub. And third, the DIY cost is displayed to two decimals, half-up, and a DIY cost that displays as $816.73 can sit a hair below the displayed figure: a $449.95 tub, $79.40 of supplies and 5.5 hours at $52.25 an hour gives 816.725, which displays as $816.73 — all listed in Accuracy & limitations.

The worked example, line by line

Setup: tub $450, supplies $80, 6 hours, $55 an hour, pro $1,100.

Line 1 — the DIY cost. $450 + $80 + 6 × $55 = $860.00.

Line 2 — the win. $1,100.00 − $860.00 = $240.00.

Line 3 — the check. At $96 an hour the DIY cost is $1,106.00 and hiring wins by $6.00; and at $95 an hour it is $1,100.00 — a dead heat, a TIE.

Every branch, checked

Hours 4: DIY $750.00; pro $1,100.00 — DIY wins by $350.00 — With 4 hours the DIY cost falls to $750.00 and DIY wins by $350.00.

Hours 8: DIY $970.00; pro $1,100.00 — DIY wins by $130.00 — With 8 hours the DIY cost rises to $970.00 and DIY wins by $130.00.

Hours 10: DIY $1,080.00; pro $1,100.00 — DIY wins by $20.00 — With 10 hours the DIY cost rises to $1,080.00 and DIY wins by $20.00.

Hours 11: DIY $1,135.00; pro $1,100.00 — Hiring wins by $35.00 — With 11 hours the DIY cost rises to $1,135.00 and hiring wins by $35.00.

Tub $650: DIY $1,060.00; pro $1,100.00 — DIY wins by $40.00 — With a $650 tub the DIY cost rises to $1,060.00 and DIY wins by $40.00.

Tub $250: DIY $660.00; pro $1,100.00 — DIY wins by $440.00 — With a $250 tub the DIY cost falls to $660.00 and DIY wins by $440.00.

Supplies $150: DIY $930.00; pro $1,100.00 — DIY wins by $170.00 — With $150 of supplies the DIY cost rises to $930.00 and DIY wins by $170.00.

Hourly $75: DIY $980.00; pro $1,100.00 — DIY wins by $120.00 — At $75 an hour the DIY cost rises to $980.00 and DIY wins by $120.00.

Pro $900: DIY $860.00; pro $900.00 — DIY wins by $40.00 — Against a $900 pro quote the DIY cost is $860.00 and DIY wins by $40.00.

The reverses, worked backwards

Smallest hourly value where hiring WINS: At the displayed $96 the figures are DIY $1,106.00; pro $1,100.00 — Hiring wins by $6.00. At $95 an hour the figures are DIY $1,100.00; pro $1,100.00 — exact tie — a dead heat, a TIE — so $96 an hour is the smallest hourly value where hiring wins.

Largest hourly value where DIY still wins by at least $100.00: At the displayed $78 the figures are DIY $998.00; pro $1,100.00 — DIY wins by $102.00. At $79 an hour the figures are DIY $1,004.00; pro $1,100.00 — DIY wins by $96.00 — DIY wins by $96.00 — below the $100.00 target — so $78 an hour is the largest hourly value where DIY still wins by at least $100.00.

Smallest tub price where hiring WINS: At the displayed $691 the figures are DIY $1,101.00; pro $1,100.00 — Hiring wins by $1.00. At $690 the figures are DIY $1,100.00; pro $1,100.00 — exact tie — a dead heat, a TIE — so $691 is the smallest tub price where hiring wins.

Smallest hours where hiring WINS: At the displayed 11 hours the figures are DIY $1,135.00; pro $1,100.00 — Hiring wins by $35.00. At 10 hours the figures are DIY $1,080.00; pro $1,100.00 — DIY wins by $20.00 — DIY wins by $20.00 — no tie — so 11 hours is the smallest hours where hiring wins.

Smallest supplies where hiring WINS: At the displayed $321 the figures are DIY $1,101.00; pro $1,100.00 — Hiring wins by $1.00. At $320 of supplies the figures are DIY $1,100.00; pro $1,100.00 — exact tie — a dead heat, a TIE — so $321 is the smallest supplies where hiring wins.

Smallest pro price where DIY WINS at all: At the displayed $861 the figures are DIY $860.00; pro $861.00 — DIY wins by $1.00. At $860 the figures are DIY $860.00; pro $860.00 — exact tie — a dead heat, a TIE — so $861 is the smallest pro price where DIY wins at all.

A warning about the ties: at $95 an hour the DIY cost is $1,100.00 — a dead heat, a TIE, not a hiring win — and at $96 it is $1,106.00 and hiring wins by $6.00. At $690 of tub price the DIY cost is $1,100.00 — a dead heat, a TIE — and at $691 it is $1,101.00 and hiring wins by $1.00. At $320 of supplies the DIY cost is $1,100.00 — a dead heat, a TIE — and at $321 it is $1,101.00 and hiring wins by $1.00. At $860 of pro price the pro cost is $860.00 — a dead heat, a TIE, not a DIY win — and at $861 it is $861.00 and DIY wins by $1.00. There is no tie at $78 an hour or 10 hours: at $78 DIY wins by $102.00 and at $79 DIY wins by $96.00; at 10 hours DIY wins by $20.00 and at 11 hours hiring wins by $35.00.

What the defaults assume

The defaults are a $450 tub, $80 of supplies, 6 hours at $55 an hour and a $1,100 pro quote — DIY $860.00; pro $1,100.00 — DIY wins by $240.00. With Hours 4, DIY $750.00; pro $1,100.00 — DIY wins by $350.00. With Hours 8, DIY $970.00; pro $1,100.00 — DIY wins by $130.00. With Hours 10, DIY $1,080.00; pro $1,100.00 — DIY wins by $20.00. With Hours 11, DIY $1,135.00; pro $1,100.00 — Hiring wins by $35.00. With Tub $650, DIY $1,060.00; pro $1,100.00 — DIY wins by $40.00. With Tub $250, DIY $660.00; pro $1,100.00 — DIY wins by $440.00. With Supplies $150, DIY $930.00; pro $1,100.00 — DIY wins by $170.00. With Hourly $75, DIY $980.00; pro $1,100.00 — DIY wins by $120.00. With Pro $900, DIY $860.00; pro $900.00 — DIY wins by $40.00. With All zero, DIY $0.00; pro $0.00 — exact tie — no tub, no supplies, no hours, no pro quote — a dead heat. With Tub $300, supplies $50, 4 hours, $50 an hour, pro $700, DIY $550.00; pro $700.00 — DIY wins by $150.00 — a small job with a cheap tub and a low pro quote. With Fractional inputs (DIY unrounded 816.725, win unrounded 82.875), DIY $816.73 (unrounded 816.725); pro $899.60 — DIY wins by $82.88 (unrounded 82.875) — the DIY cost displays as $816.73. With Tub $900, supplies $200, 10 hours, $80 an hour, pro $2,500, DIY $1,900.00; pro $2,500.00 — DIY wins by $600.00 — the same win at four times the size. With Pro $860, DIY $860.00; pro $860.00 — exact tie — a dead heat, a TIE. With Tub $0, supplies $40, 3 hours, $45 an hour, pro $400, DIY $175.00; pro $400.00 — DIY wins by $225.00 — a tub you already own, so the DIY cost is mostly your time.

A note on the rounding: the DIY cost is displayed to two decimals, half-up. With the fractional inputs the unrounded DIY cost is 816.725 and the unrounded win is 82.875 — they display as $816.73 and $82.88. The page prints the unrounded values so the rounding does not mislead you.

Output · formula · meaning

Who uses this

• The homeowner replacing a bathtub: they learn a $450 tub, $80 of supplies and 6 hours at $55 an hour costs $860.00 DIY against a $1,100.00 pro quote — and they check the $96 reverse to see the hourly value where hiring takes the lead.
• The renter fitting a new tub: they learn the supplies are the drain, the overflow, the sealant and the waste pipe, not the tub alone — and they check the $691 reverse to see the tub price where hiring wins.
• The weekend DIYer pricing their time: they learn 6 hours at $55 an hour is $330 of their own time — and they check the 11-hour reverse to see the hours where hiring wins.
• The landlord comparing quotes: they learn an $860.00 DIY cost against a $1,100.00 pro quote is a $240.00 win — and they check the $861 reverse to see the pro price where DIY wins at all.

Accuracy & limitations

The math is first-principles: the DIY cost is the tub price plus the supplies plus the hours times your hourly value, and the win is the pro cost minus the DIY cost — all in dollars, displayed to two decimals half-up. There is no division in this calculator — nothing is ever undefined. At a $95 hourly value the DIY cost is $1,100.00 — a dead heat, a TIE, not a hiring win — and at $690 of tub price the DIY cost is $1,100.00 — a dead heat, a TIE. With the fractional inputs the unrounded DIY cost is 816.725 and the unrounded win is 82.875 — they display as $816.73 and $82.88. What the model cannot do is price the risk: it says nothing about a leak under the tub, a drain that will not seal, or a pro who guarantees the work. It also says nothing about whether the pro quote includes the tub — check that before you compare, or the comparison is wrong before it starts. Use it to see whether fitting the bathtub yourself saves money — then check the shower, toilet, sink and faucet comparisons before you decide the whole bathroom is a DIY job.

Frequently asked questions