# Variation Order Cost Calculator

Full cost of a variation and the change against the original rate.

- Page: https://jianzhujisuan.com/en/variation-order
- Category: Costing (https://jianzhujisuan.com/en/c/costing)
- Chinese version: https://jianzhujisuan.com/zh/variation-order.md
- Data checked: 2026-10-25

## Quick result

With the default inputs (Variation quantity 500, New rate 145 CNY, Original rate 120 CNY, Preliminaries rate 8%, Levy rate 3%, Tax rate 9%): **Total variation cost 87907 CNY**

## Inputs

| Parameter | Type | Default | Unit | Note |
|---|---|---|---|---|
| Variation quantity | number | 500 | — |  |
| New rate | number | 145 | CNY |  |
| Original rate | number | 120 | CNY |  |
| Preliminaries rate | number | 8 | % |  |
| Levy rate | number | 3 | % |  |
| Tax rate | number | 9 | % |  |

## Formula

- **Direct cost**: quantity × new rate
- **Preliminaries**: direct × rate
- **Levy**: (direct + preliminaries) × rate
- **Tax**: subtotal × rate
- **Total**: direct + preliminaries + levy + tax
- **Change**: total − quantity × original rate

## Worked example

500 units at a new rate of 145 against 120, with 8% preliminaries, 3% levy and 9% tax: 72500 direct, 5800 preliminaries, 2349 levy, 80649 pre-tax and 7258 tax — 87907 in total, 12907 above the original rate.

## Questions

### Why do variations always get cut?

Because three things are missing: the instruction showing who ordered the change, evidence it happened — photographs, inspection records, delivery notes — and the build-up showing why that rate. Auditors work on no instruction, no claim; no evidence, no measurement; no build-up, no price. The classic mistake is doing the work first and signing afterwards, when the client is no longer in a hurry and the leverage has flipped.

### When can a rate be re-priced?

Three cases: no identical or similar item exists in the bill; the quantity changes by more than 15% so the rate becomes unreasonable at the new volume; or a design change alters the method or specification materially. Otherwise the original rate stands. Re-pricing needs a labour, material and plant build-up, and auditors check consumption and market rates line by line, cutting anything inflated.

### How does a site instruction differ from a design change?

A design change is a drawing revision issued by the designer and confirmed by the client, with formal paperwork; a site instruction records small or temporary work on the spot — hitting an obstruction, temporary propping, acceleration measures. Both are valued at settlement, but site instructions carry a higher evidential bar because they confirm after the event, so they are the first thing questioned in audit. Sign them the same day, with photographs.

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