diff --git a/pkg/source/limitorder/pool_simulator.go b/pkg/source/limitorder/pool_simulator.go
index 8daf437ec..ec90bd2d0 100644
--- a/pkg/source/limitorder/pool_simulator.go
+++ b/pkg/source/limitorder/pool_simulator.go
@@ -107,10 +107,6 @@ func (p *PoolSimulator) CalcAmountOut(param pool.CalcAmountOutParams) (*pool.Cal
 	return p.calcAmountOut(param.TokenAmountIn, param.TokenOut, param.Limit)
 }
 
-func (p *PoolSimulator) CalcAmountIn(param pool.CalcAmountInParams) (*pool.CalcAmountInResult, error) {
-	return p.calcAmountIn(param.TokenAmountOut, param.TokenIn, param.Limit)
-}
-
 func (p *PoolSimulator) UpdateBalance(params pool.UpdateBalanceParams) {
 	swapInfo, ok := params.SwapInfo.(SwapInfo)
 	if !ok {
@@ -169,30 +165,6 @@ func (p *PoolSimulator) calcAmountOut(
 	}, nil
 }
 
-func (p *PoolSimulator) calcAmountIn(
-	tokenAmountOut pool.TokenAmount,
-	tokenIn string,
-	limit pool.SwapLimit,
-) (*pool.CalcAmountInResult, error) {
-	swapSide := p.getSwapSide(tokenIn, tokenAmountOut.Token)
-	amountIn, swapInfo, feeAmount, err := p.calcAmountInWithSwapInfo(swapSide, tokenAmountOut, limit)
-	if err != nil {
-		return nil, err
-	}
-	return &pool.CalcAmountInResult{
-		TokenAmountIn: &pool.TokenAmount{
-			Token:  tokenIn,
-			Amount: amountIn,
-		},
-		Fee: &pool.TokenAmount{
-			Token:  tokenIn,
-			Amount: feeAmount,
-		},
-		Gas:      p.estimateGas(len(swapInfo.FilledOrders)),
-		SwapInfo: swapInfo,
-	}, nil
-}
-
 func addFilledMakingAmount(
 	filledMakingAmountByMaker map[string]*big.Int,
 	maker string,
diff --git a/pkg/source/limitorder/pool_simulator_calc_amount_in.go b/pkg/source/limitorder/pool_simulator_calc_amount_in.go
index c4f0af709..cc2a0ead9 100644
--- a/pkg/source/limitorder/pool_simulator_calc_amount_in.go
+++ b/pkg/source/limitorder/pool_simulator_calc_amount_in.go
@@ -8,6 +8,34 @@ import (
 	constant "github.com/KyberNetwork/kyberswap-dex-lib/pkg/util/bignumber"
 )
 
+func (p *PoolSimulator) CalcAmountIn(param pool.CalcAmountInParams) (*pool.CalcAmountInResult, error) {
+	return p.calcAmountIn(param.TokenAmountOut, param.TokenIn, param.Limit)
+}
+
+func (p *PoolSimulator) calcAmountIn(
+	tokenAmountOut pool.TokenAmount,
+	tokenIn string,
+	limit pool.SwapLimit,
+) (*pool.CalcAmountInResult, error) {
+	swapSide := p.getSwapSide(tokenIn, tokenAmountOut.Token)
+	amountIn, swapInfo, feeAmount, err := p.calcAmountInWithSwapInfo(swapSide, tokenAmountOut, limit)
+	if err != nil {
+		return nil, err
+	}
+	return &pool.CalcAmountInResult{
+		TokenAmountIn: &pool.TokenAmount{
+			Token:  tokenIn,
+			Amount: amountIn,
+		},
+		Fee: &pool.TokenAmount{
+			Token:  tokenIn,
+			Amount: feeAmount,
+		},
+		Gas:      p.estimateGas(len(swapInfo.FilledOrders)),
+		SwapInfo: swapInfo,
+	}, nil
+}
+
 func (p *PoolSimulator) calcAmountInWithSwapInfo(swapSide SwapSide, tokenAmountOut pool.TokenAmount, limit pool.SwapLimit) (*big.Int, SwapInfo, *big.Int, error) {
 	orderIDs := p.getOrderIDsBySwapSide(swapSide)
 	if len(orderIDs) == 0 {