Space bars or slats evenly across any frame. Enter your frame size and bar width — get exact gap measurements.
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✂
Cut List
Plan your cuts before ordering. Know how many lengths to buy, cuts per length, offcut sizes, and waste percentage.
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Weight Calculator
Calculate your total order weight before heading to the supplier. Includes a vehicle load indicator so you know what you can carry.
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Angle Cuts
Get short point, long point, and a cut diagram for any angle. Mark directly from the diagram — no guesswork at the grinder.
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Welding Rod Estimator
Not sure which rod to use or how many to buy? Get a rod recommendation for your job and an accurate quantity estimate.
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R
Job Costing
Price your work properly. Calculate material, labour, and consumable costs — then generate a clean client quote in your local currency.
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Bolt Spacing
Space bolts, screws, rivets, or hinges evenly along any length of steel, timber, or plate.
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Drill Reference
Tap drill, clearance drill, and countersink size for any bolt. Metric and imperial.
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MIG Wire Estimator
Wire diameter, joint type, material thickness — get kg needed and reels to buy.
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Settings Guide
Recommended MIG or flux core settings for your machine and material.
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Job Timer
Track time spent on each task. Send the total straight to Job Costing.
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Paint Coverage
Estimate how much paint, primer, or rust converter your job needs.
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Sheet Metal Flat Pattern
Correct flat blank size before bending. Bend allowance with K-factor per material.
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Pipe & Tube Bending
Developed length and overbend angle — get exact marks before you bend.
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Weld Troubleshooter
Fix porosity, spatter, burn-through — right now.
The formula
n = floor( (L + g) / (w + g) )
g_actual = (L − n×w) / (n − 1)
Bars run edge-to-edge. Gaps exist only between bars — not at the ends.
Frame Dimension (spacing direction)
Frame length — the side your bars span acrossL
mm
Bar / Slat Width
Width of each flat bar or slatw
mm
Target Gap
Gap you're aiming for between barsg
mm
Bar Cut Length (optional — for materials list)
Length to cut each bar — usually the other frame dimensionb
mm
Stock length you buy from (usually 6m)S
mm
Measure twice, cut once. Enter your raw stock length, how long you want each piece, and how many you need. GapCalc tells you cuts per length, lengths to buy, offcut lengths — before you touch the grinder.
Raw Stock
Length of each piece you buyS
mm
Desired Piece Length
Length of each piece you want to cutp
mm
Quantity Needed
Total number of pieces requiredQ
pcs
Blade Kerf (optional)
Material lost per cut (angle grinder disc ≈ 1–2mm)k
mm
Know before you go. Calculate the total weight of your steel or timber order before heading to the supplier — so you know if your vehicle can handle it.
Material
Steel Grade
Steel Profile
Timber Species
Select species for accurate density
Custom density
g/cm³
Dimensions
Order Details
Length per pieceL
mm
Number of lengthsQ
pcs
The formula
cut face = width / sin(θ)
long point = short point + (width / tan(θ))
Bars run edge-to-edge. Mark from short point and long point — draw a line between them.
Cut Type
How are the two cuts oriented?
Material Width
Width of the face being cut acrossw
mm
Piece Length (short point to short point)
The dimension you're cutting to — measured on the short sideL
mm
Cut Angle
Angle of the cut measured from square (90° = straight cut)θ
deg
Your Skill Level
Be honest — this helps the tool give you the right guidance and a realistic quantity estimate.
PART 1 — ROD SELECTOR
Base Material
What metal are you welding?
Joint Type
How are the two pieces of metal meeting?
Weld Position
The position you will be welding in. Shown with industry code for reference.
PART 2 — ROD QUANTITY ESTIMATOR
Material Thickness
Thickness of the thinner piece being weldedt
mm
Rod Diameter
Select the rod size you are using. If unsure, 2.5mm is a good starting point for most hobby welders.
Suggested based on your material thickness. You can override this.
Total Weld Length
How many individual welds (joints) does this job have? Then pick the approximate size of each weld.
Number of joints
pcs
Approximate weld size per joint:
Add up the total length of all your welds combined and enter it here.
Total weld lengthW
mm
Price your work properly. Enter your materials, labour, and consumables. GapCalc calculates your cost, suggests a sell price, and generates a clean quote for your client — keeping your margins private.
Currency
All amounts will display in your selected currency. Enter your local prices.
YOUR BUSINESS DETAILS
+
Tip: Keep your business details handy to paste in quickly — the app won't save these between sessions.
Quote #
Write this down — the app won't remember it next time.
Business name
Address
Phone
Email
Website
VAT number
Client Details
Client / company name
Contact person
Address
Phone
Email
Client VAT number
Client company reg number
Quote Info
Quote date
Valid until
Payment terms
VAT registered — include VAT on quote
VAT Rate
%
Standard SA VAT is 15%. Adjust if your region uses a different rate.
Materials
DescriptionQtyUnit Price
Consumables
Rods, grinding discs, wire, gas, primer, paint — every small cost adds up. Don't leave money on the table.
DescriptionQtyUnit Price
Labour
Your hourly rate
R/hr
Hours on this job
hrs
Flat labour fee for this job
R
Delivery
You will deliver the finished product to the client
Distance to client
km
Fuel price
R/L
Fuel consumption
L/100km
Your time cost (hourly)
R/hr
Estimated delivery time (one way)
hrs
Margin & Pricing
Your target gross margin%
%
Markup vs Margin — know the difference
Markup is added on top of your cost. A 30% markup on 1,000 = 1,300 sell price. Margin is your profit as a percentage of your sell price. A 30% margin on 1,000 cost = 1,429 sell price. Same profit goal — different numbers. This tool uses margin.
Same model as the Gap Calculator — fixings fill edge to edge, gaps only between them.
Surface Length
The length you are spacing fixings alongL
mm
Fixing Diameter
Diameter of the bolt hole or fixingd
mm
Target Spacing
Desired spacing between fixingsg
mm
Spacing measurement method:
Measured from centre of one fixing to centre of the next — standard engineering practice
Always have the right drill. Select your thread size to instantly get tap drill, clearance drill, and countersink dimensions — no more guessing at the drill index.
Thread Standard
Select thread size:
Select thread size:
M6 — DRILL SIZES
Tap Drill
—
Drill this size before tapping threads
Clearance Drill
—
Drill this size for a bolt to pass through freely
Countersink
—
Use this size for a countersunk head
Your Skill Level
Be honest — this adjusts the wire quantity for realistic wastage.
PART 1 — WIRE SELECTOR
Shielding Gas
Select your shielding gas mix.
C25 is the workshop standard — clean welds, minimal spatter, works well on mild steel 1.5–6mm. Set voltage and wire speed per your machine's chart.
PART 2 — WIRE QUANTITY ESTIMATOR
Material Thickness
Thickness of the thinner piece being weldedt
mm
Wire Diameter
Select the wire diameter for your job.
Suggested based on your material thickness. You can override this.
Joint Type
How are the two pieces of metal meeting?
Total Weld Length
How many individual welds does this job have?
Number of joints
pcs
Approximate weld size per joint:
Add up the total length of all your welds combined and enter it here.
Total weld lengthW
mm
These are starting point recommendations only. Every machine, wire brand, and material combination behaves differently. Use these settings as a baseline — then adjust based on what your weld is telling you. A good weld sounds like frying bacon. If you're getting spatter, porosity, or burn-through, the settings need adjusting regardless of what any guide says.
Welding Process
What controls does your machine have?
Only turn on what your machine actually has. This keeps the output relevant to your setup.
Voltage control
Controls heat input. Higher voltage makes a wider, flatter bead. Lower voltage makes a narrower, more built-up bead.
Wire feed speed control
Controls how fast wire enters the weld. Too fast and the wire stubs into the work. Too slow and it burns back toward the tip.
Inductance control
Controls how smooth or crisp the arc feels. Higher inductance means a smoother arc with less spatter. Not all machines have this.
Material
Material Thickness
Thickness of the thinner piece being weldedt
mm
Wire Diameter
Suggested based on your material thickness. You can override this.
POLARITY — CHECK THIS FIRST
Flux core wire requires a specific polarity setting that is the OPPOSITE of solid MIG wire.
Your torch lead → plug into the NEGATIVE (−) terminal on your machine. Your earth clamp → plug into the POSITIVE (+) terminal on your machine.
This is called DCEN (DC Electrode Negative). Some machines label it as 'straight polarity'.
If you just switched from solid wire to flux core and your welds look terrible — wrong polarity is almost always the reason. Swap your leads before changing anything else.
Start a task, run the timer, stop when done. Add as many tasks as your job needs. Your tasks are saved in this browser automatically — they will still be here if you close and reopen this tab. Clearing your browser data or using private/incognito mode will reset the timer.
Current Task
00:00:00
Job Log
No tasks recorded yet. Start your first task above.
Total Job Time0:00:00
Select your paint type first — changing it will reset the calculator so you get a fresh result for each coat.
PAINT TYPE
Select your coating. The calculator resets when you change this.
CAN SIZE
~1.5 m² per coat — standard rattle can
Can size
ml
SURFACE AREA
Total surface area
m²
Shape
Length
mm
Width
mm
Sides to paint
Length
mm
Width
mm
Height
mm
Include inside faces
Outer diameter
mm
Length
mm
Leg width
mm
Leg height
mm
Length
mm
Calculates both legs, outer faces only
Section perimeter
mm
Measure around the outside of your section profile
Length
mm
Number of pieces
pcs
COATS
coats
Most jobs need 2 coats for full coverage and durability.
Calculate your flat blank size before making a single cut. Enter your finished dimensions and let GapCalc work backwards to give you the correct flat length to cut.
MATERIAL
MATERIAL THICKNESS
mm
INSIDE BEND RADIUS
mm
The radius of your die or former — measure on the inside of the bend. A tighter radius increases springback.
BEND ANGLE
°
The final angle of the bend — not the angle you press to.
FACE DIMENSIONS
Face A
mm
First flat face length
Face B
mm
Second flat face length
Know your marks before you bend. Enter your tube dimensions and target angle — GapCalc tells you the developed length and where to mark your tube.
MATERIAL
TUBE DIMENSIONS
Outside diameter (OD)
mm
Wall thickness
mm
CENTRELINE BEND RADIUS
mm
Measure from the centre of the tube to the centre of the bend arc. Minimum recommended: 3 × outside diameter to avoid kinking.
BEND ANGLE (TARGET)
°
The finished angle you want to achieve — not the angle you press to.