Why does the base type matter if the colourant is the same?

Because the base decides how much colourant the paint can carry before the film stops working, and that limit has nothing to do with the shade you are aiming at. Colourant is pigment suspended in a vehicle that contributes very little binder — it is there to colour the paint, not to help it form a film. So every unit you add dilutes the binder that has to hold the whole lot together. A pastel base is mostly titanium white and is formulated on the assumption that only a small load is coming; a deep or accent base is made with far less white and correspondingly more room. Push a pastel base to a deep-base load and you get a paint that looks right in the tin and right on the wall the same day, and then dries slowly, stays soft for weeks, blocks where anything rests against it, marks with a fingernail and wears out early. It is one of the few paint mistakes that is genuinely invisible at the time and irreversible afterwards, which is why the page treats exceeding the limit as a reason to drop its own confidence rather than as a note at the bottom.

Why is the load a percentage rather than ounces per gallon?

Because a percentage scales and an ounce-per-gallon figure has to be converted every time the batch size changes, which is where the errors come in. A load expressed as a share of the base is the same number whether you are tinting a sample pot, a five litre tin or a twenty litre tub — multiply and you have the answer. It also reads identically in both markets, which an ounce-per-gallon figure does not. The conversion is simple and the page gives it in both directions: one US fluid ounce per US gallon is one part in 128, which is 0.78 per cent, and one per cent is ten millilitres per litre. So a 4 oz/gal formula off a shop ticket is a 3.1 per cent load, and 12 oz/gal is 9.4. The output is still given in the small units colourant is actually dispensed in, because that is what you measure into the tin — the percentage is for carrying the formula between batch sizes, not for holding the syringe.

Can I tint a paint that was not sold as a base?

Usually not well, and sometimes not at all. A ready-mixed white is not the same product as a white base: it is formulated to be finished, with its pigment and binder already in balance, and it has no headroom designed into it. Adding colourant to it works in very small amounts and quickly runs into the same soft-film problem as over-loading a base, with less warning because there is no stated limit to exceed. Tinting a coloured ready-mixed paint is a different exercise again, closer to the mixing calculator's territory — you are combining two finished products rather than loading a base, and the result is unpredictable in colour and only roughly predictable in behaviour. The practical position is that small adjustments to a finished paint are an ordinary trade thing to do and large ones are not, and that anything you intend to reproduce later should start from a base and a recorded formula rather than from a tin you adjusted by eye.

The shop's machine gave me a formula in units I do not recognise. What do I do?

Tinting machines dispense in fractional units that mean nothing outside their own system — commonly ounces plus a fraction written as something like 2Y12, meaning two ounces and twelve forty-eighths, or in shots and grams depending on the make. Those are instructions to a machine that knows its own colourant strengths, and they are not portable: the same code in another manufacturer's system is a different quantity of a different colourant. If you are having the paint made up, none of this matters, because the machine does the work and the formula stays with the tin. It matters when you are hand-tinting, scaling a formula to an unusual batch size, or trying to repeat a colour later. Then the only figure worth carrying is the total colourant volume actually dispensed, which the shop can tell you, converted to a percentage of the base — because that number survives a change of batch size and can be checked with a syringe. Keep it written on the lid with the base type beside it.

Renovation & Construction

Paint Tint Ratio and Colourant Load Calculator

The colourant a batch needs for a stated tint load, scaled from any formula to any batch size, and whether the base you are using can actually carry it.

Answers as you typeNo submit button
Every formula citedNamed published standards
Calculated in your browserNo account, nothing uploaded

SettingsSettings for this calculationUS

Market

Imperial · sales tax

Base paint to be tinted

How much base paint the batch starts from.

The base alone, before colourant. Tins are filled leaving room for it, so a nominally full tin of base is not quite full — if you are tinting a whole tin, use the volume printed on it and expect the finished quantity to be slightly more than that.

Tint load, as a percentage of the base by volume

The formula's colourant load, as a percentage of the base.

A shop formula states a colourant volume per unit of base; this page works in the equivalent percentage, and the FAQ below converts between the two in both directions. Where a formula lists several colourants, add their loads together and enter the total — a base's limit is on everything that goes into it, not on any one colourant.

Base type

Which base the colour is being made in.

Printed on the tin, usually near the product name, and it is not cosmetic: it decides how much colourant the paint can carry before the film suffers. A colour that needs a deep base cannot be reached by over-loading a pastel one, however close the shade looks while it is wet.

Colourant for the batch

0.03875 gal

High confidence

5.0 fl oz into 1.25 gal is a 3.10% load — 4.0 fl oz per US gallon. That leaves about 0.0 percentage points of headroom on this base. A pastel base is mostly white and has the least room for colourant of any base; it is meant for tints, not for depth. The colourant volume is exact; the shade it produces is not predicted here. What a given load makes depends on absorption and scattering measured per pigment, which is what the shop's tinting machine holds and does not publish. This page answers how much, and a sample pot answers what colour.

Base paint: 1.25 gal
Finished batch: 1.29 gal
Load in the units a formula is written in: 3.97 fl oz per US gal
This base's typical maximum: 3.1 %
Headroom left: 0 percentage points

Then change the inputs to see how far the answer moves.

Show calculation logic

How this was calculated

Formula source(s)

Tint load is expressed as a percentage of the BASE volume, which scales to any batch size without conversion. One US fluid ounce per US gallon is 1/128 of the base, or 0.78 per cent — so a 4 oz/gal formula is a 3.1 per cent load
Every base has a MAXIMUM load. Colourant is pigment in a vehicle that contributes little binder, so an over-loaded film stays soft, dries slowly, blocks and marks. Deep and accent bases exist because they are formulated with less white and more room for colourant — the figures used here are typical shelf values and the product's own tinting system governs
No colour is predicted or displayed. What load produces what shade depends on per-pigment absorption and scattering coefficients that are not published, and an uncalibrated screen could not show the answer faithfully in any case

Inputs used

Base paint to be tinted: 1.25 gal
Tint load, as a percentage of the base by volume: 3.1
Base type: White or pastel base (about 4 fl oz per US gallon)

Intermediate steps

Base paint: 1.25 gal
Finished batch: 1.29 gal
Load in the units a formula is written in: 3.97 fl oz per US gal
This base's typical maximum: 3.1 %
Headroom left: 0 percentage points

Final result0.04 gal

Confidence note: 5.0 fl oz into 1.25 gal is a 3.10% load — 4.0 fl oz per US gallon. That leaves about 0.0 percentage points of headroom on this base. A pastel base is mostly white and has the least room for colourant of any base; it is meant for tints, not for depth. The colourant volume is exact; the shade it produces is not predicted here. What a given load makes depends on absorption and scattering measured per pigment, which is what the shop's tinting machine holds and does not publish. This page answers how much, and a sample pot answers what colour.

What this calculation does not cover

The colourant volume is exact; the shade it produces is not predicted here. What a given load makes depends on absorption and scattering measured per pigment, which is what the shop's tinting machine holds and does not publish. This page answers how much, and a sample pot answers what colour.
The maximum loads here are TYPICAL shelf figures for each base class, not a specification. Every manufacturer's tinting system sets its own limits, its own colourant strengths and its own base range, and the machine in the shop is following that system rather than this table. Where a formula from the product's own system exceeds these figures, the system is right and this page is the approximation.
AN OVER-LOADED FILM FAILS QUIETLY AND LATE. Colourant is pigment in a vehicle that adds little binder, so past a base's limit the paint has more pigment than the binder can hold: it dries slowly, stays soft, blocks against anything left resting on it, marks with a fingernail and wears early. None of that is visible while the paint is wet, or on the day it is applied, which is why the base type matters more than it looks.
Where a formula lists several colourants, add the loads together before entering them. The limit is on the TOTAL that goes into the base, not on any one colourant, and a formula made of four modest additions can exceed a base's capacity while no single line looks large.
Colourant strength is not standardised between brands. A universal colourant and a manufacturer's own are different products at different pigment concentrations, so a load that is right in one system is a different colour and a different load in another. Matching a formula across systems is a job for the machine, not for arithmetic.
Stir to complete uniformity before judging anything, and longer than looks necessary. Colourant disperses through the base faster than the base itself circulates, so a batch that already looks even can still be layered — particularly in a tall vessel. Judge the result dry, at full opacity, in the light the wall will live in.

Estimated cost — your price

Price per gal ($)

This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.

Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.

Sources checked 2026-09-15 · v1.0.0

Regulatory standards & verification citations3

Tint load is expressed as a percentage of the BASE volume, which scales to any batch size without conversion. One US fluid ounce per US gallon is 1/128 of the base, or 0.78 per cent — so a 4 oz/gal formula is a 3.1 per cent load
Every base has a MAXIMUM load. Colourant is pigment in a vehicle that contributes little binder, so an over-loaded film stays soft, dries slowly, blocks and marks. Deep and accent bases exist because they are formulated with less white and more room for colourant — the figures used here are typical shelf values and the product's own tinting system governs
No colour is predicted or displayed. What load produces what shade depends on per-pigment absorption and scattering coefficients that are not published, and an uncalibrated screen could not show the answer faithfully in any case

Cite this page

Your workspace

Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Protection this work requires

Stop and check first. Paint under later coats in older housing can be lead-based, and sanding or heat-stripping it produces lead dust that is especially harmful to children and to anyone pregnant. Test before you disturb it — this is a job for a tested, controlled method, not a better mask.

Tools and safety for this job

To roll and cut in two coats and prepare a surface for paint. Generic types, no brands, no prices.

Joint-compound dust is very fine and travels: a P1/FFP1 mask is the minimum, and a damp-sponge finish avoids most of it.
A dust mask does nothing about solvent vapour: ventilate through, and use an organic-vapour (A1) cartridge respirator in an enclosed room.
Most fatal falls on small jobs are from under three metres: use a tower or a ladder tied at the top, and never work off the top two rungs.

Show the 11 tools this job needs

Essential

Brushes
Dust sheets and masking
Filling knife
Roller frame, sleeves and tray
Scraper

Recommended

Caulking gun
Extension pole
Pole sander
Random orbital sander
Step ladder

Optional

Dust extractor or vacuum with a fine filter

Also needed as materials: abrasive discs, caulk and sealant cartridges, masking tape, plastic sheeting, roller sleeves, sanding screens or paper.

what each painting tool is for, and the spec that decides which to buy where one does.

The data behind it: Production rates by operation

How to calculate paint tint ratio and colourant load in 4 steps

Base paint to be tintedHow much base paint the batch starts from.
Tint load, as a percentage of the base by volumeThe formula's colourant load, as a percentage of the base.
Base typeWhich base the colour is being made in.
Colourant for the batchThe tool computes the colourant for the batch from those figures and shows the formula, its sources, and a confidence rating alongside it.

Colourant for the batch by base paint to be tinted

Page defaults, not your figures above.

Base paint to be tinted	Colourant for the batch (gal)
1 gal	0.031
1.5 gal	0.046
2 gal	0.062
2.5 gal	0.078

Frequently asked questions

Why does the base type matter if the colourant is the same?: Because the base decides how much colourant the paint can carry before the film stops working, and that limit has nothing to do with the shade you are aiming at. Colourant is pigment suspended in a vehicle that contributes very little binder — it is there to colour the paint, not to help it form a film. So every unit you add dilutes the binder that has to hold the whole lot together. A pastel base is mostly titanium white and is formulated on the assumption that only a small load is coming; a deep or accent base is made with far less white and correspondingly more room. Push a pastel base to a deep-base load and you get a paint that looks right in the tin and right on the wall the same day, and then dries slowly, stays soft for weeks, blocks where anything rests against it, marks with a fingernail and wears out early. It is one of the few paint mistakes that is genuinely invisible at the time and irreversible afterwards, which is why the page treats exceeding the limit as a reason to drop its own confidence rather than as a note at the bottom.
Why is the load a percentage rather than ounces per gallon?: Because a percentage scales and an ounce-per-gallon figure has to be converted every time the batch size changes, which is where the errors come in. A load expressed as a share of the base is the same number whether you are tinting a sample pot, a five litre tin or a twenty litre tub — multiply and you have the answer. It also reads identically in both markets, which an ounce-per-gallon figure does not. The conversion is simple and the page gives it in both directions: one US fluid ounce per US gallon is one part in 128, which is 0.78 per cent, and one per cent is ten millilitres per litre. So a 4 oz/gal formula off a shop ticket is a 3.1 per cent load, and 12 oz/gal is 9.4. The output is still given in the small units colourant is actually dispensed in, because that is what you measure into the tin — the percentage is for carrying the formula between batch sizes, not for holding the syringe.
Can I tint a paint that was not sold as a base?: Usually not well, and sometimes not at all. A ready-mixed white is not the same product as a white base: it is formulated to be finished, with its pigment and binder already in balance, and it has no headroom designed into it. Adding colourant to it works in very small amounts and quickly runs into the same soft-film problem as over-loading a base, with less warning because there is no stated limit to exceed. Tinting a coloured ready-mixed paint is a different exercise again, closer to the mixing calculator's territory — you are combining two finished products rather than loading a base, and the result is unpredictable in colour and only roughly predictable in behaviour. The practical position is that small adjustments to a finished paint are an ordinary trade thing to do and large ones are not, and that anything you intend to reproduce later should start from a base and a recorded formula rather than from a tin you adjusted by eye.
The shop's machine gave me a formula in units I do not recognise. What do I do?: Tinting machines dispense in fractional units that mean nothing outside their own system — commonly ounces plus a fraction written as something like 2Y12, meaning two ounces and twelve forty-eighths, or in shots and grams depending on the make. Those are instructions to a machine that knows its own colourant strengths, and they are not portable: the same code in another manufacturer's system is a different quantity of a different colourant. If you are having the paint made up, none of this matters, because the machine does the work and the formula stays with the tin. It matters when you are hand-tinting, scaling a formula to an unusual batch size, or trying to repeat a colour later. Then the only figure worth carrying is the total colourant volume actually dispensed, which the shop can tell you, converted to a percentage of the base — because that number survives a change of batch size and can be checked with a syringe. Keep it written on the lid with the base type beside it.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — a confirmed fix gets a permanent check of its own, so the same mistake cannot come back.